Honest Little Apps Challenge collections

Pocket Puzzle Arcade · 28 original mini-challenges

28 Number-Path Mini-Challenges with Worked Answers

Audit a route, recover a missing sum, choose matching checkpoints and spot an illegal move in 28 original number-path challenges.

Choose a response. See the reasoning.

Read the facts, pick the answer that best fits the stated goal, then open the explanation. Start with five or browse the full set. There is no timer or personal assessment; the useful part is understanding the choice.

These are original web companion exercises. They are independent of the app; answers and progress do not transfer. All people and records in the scenarios are fictional.

01 / reasoning

Pair checkpoint audit 1

A route is already drawn across this two-row board: R1C1 → R2C1 → R2C2 → R1C2 → R1C3 → R2C3. Divide that route into consecutive pairs, starting with its first cell. Which ordered list gives the three pair totals? Rows run from top to bottom; columns run left to right.

22	17	7
10	14	16

Show the worked answer

C. 32, 31, 23

Add the first two visited values, then the next two, then the last two. The pair calculations are 22 + 10 = 32; 14 + 17 = 31; 7 + 16 = 23. Order matters even when the same values appear elsewhere.

Try next: Draw a different valid route and compare which totals change.

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02 / reasoning

Pair checkpoint audit 2

A route is already drawn across this two-row board: R1C1 → R2C1 → R2C2 → R1C2 → R1C3 → R2C3. Divide that route into consecutive pairs, starting with its first cell. Which ordered list gives the three pair totals? Rows run from top to bottom; columns run left to right.

9	13	16
21	5	17

Show the worked answer

C. 30, 18, 33

Add the first two visited values, then the next two, then the last two. The pair calculations are 9 + 21 = 30; 5 + 13 = 18; 16 + 17 = 33. Order matters even when the same values appear elsewhere.

Try next: Draw a different valid route and compare which totals change.

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03 / reasoning

Pair checkpoint audit 3

A route is already drawn across this two-row board: R1C1 → R2C1 → R2C2 → R1C2 → R1C3 → R2C3. Divide that route into consecutive pairs, starting with its first cell. Which ordered list gives the three pair totals? Rows run from top to bottom; columns run left to right.

9	22	8
14	4	3

Show the worked answer

C. 23, 26, 11

Add the first two visited values, then the next two, then the last two. The pair calculations are 9 + 14 = 23; 4 + 22 = 26; 8 + 3 = 11. Order matters even when the same values appear elsewhere.

Try next: Draw a different valid route and compare which totals change.

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04 / reasoning

Pair checkpoint audit 4

A route is already drawn across this two-row board: R1C1 → R2C1 → R2C2 → R2C3 → R1C3 → R1C2. Divide that route into consecutive pairs, starting with its first cell. Which ordered list gives the three pair totals? Rows run from top to bottom; columns run left to right.

19	8	3
13	23	10

Show the worked answer

A. 32, 33, 11

Add the first two visited values, then the next two, then the last two. The pair calculations are 19 + 13 = 32; 23 + 10 = 33; 3 + 8 = 11. Order matters even when the same values appear elsewhere.

Try next: Draw a different valid route and compare which totals change.

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05 / reasoning

Pair checkpoint audit 5

A route is already drawn across this two-row board: R1C1 → R2C1 → R2C2 → R2C3 → R1C3 → R1C2. Divide that route into consecutive pairs, starting with its first cell. Which ordered list gives the three pair totals? Rows run from top to bottom; columns run left to right.

7	12	5
8	20	15

Show the worked answer

A. 15, 35, 17

Add the first two visited values, then the next two, then the last two. The pair calculations are 7 + 8 = 15; 20 + 15 = 35; 5 + 12 = 17. Order matters even when the same values appear elsewhere.

Try next: Draw a different valid route and compare which totals change.

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06 / reasoning

Pair checkpoint audit 6

A route is already drawn across this two-row board: R1C1 → R1C2 → R1C3 → R2C3 → R2C2 → R2C1. Divide that route into consecutive pairs, starting with its first cell. Which ordered list gives the three pair totals? Rows run from top to bottom; columns run left to right.

23	4	10
13	20	8

Show the worked answer

B. 27, 18, 33

Add the first two visited values, then the next two, then the last two. The pair calculations are 23 + 4 = 27; 10 + 8 = 18; 20 + 13 = 33. Order matters even when the same values appear elsewhere.

Try next: Draw a different valid route and compare which totals change.

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07 / reasoning

Pair checkpoint audit 7

A route is already drawn across this two-row board: R1C1 → R2C1 → R2C2 → R2C3 → R1C3 → R1C2. Divide that route into consecutive pairs, starting with its first cell. Which ordered list gives the three pair totals? Rows run from top to bottom; columns run left to right.

23	13	5
17	3	21

Show the worked answer

A. 40, 24, 18

Add the first two visited values, then the next two, then the last two. The pair calculations are 23 + 17 = 40; 3 + 21 = 24; 5 + 13 = 18. Order matters even when the same values appear elsewhere.

Try next: Draw a different valid route and compare which totals change.

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08 / reasoning

Missing three-cell checkpoint 1

The route R1C1 → R1C2 → R1C3 → R2C3 → R3C3 → R3C2 → R3C1 → R2C1 → R2C2 visits all nine cells once. Its consecutive groups each contain three cells. The first checkpoint total is missing from the record. Which value belongs there? Use the supplied route rather than sorting the board values.

2	21	19
13	17	16
26	22	20

Show the worked answer

B. 42

The relevant cells are R1C1 → R1C2 → R1C3. Their values are 2, 21, 19, which total 42. The other checkpoints do not change where this group starts or ends.

Try next: Circle the three cells before doing the addition, then verify the remaining checkpoints.

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09 / reasoning

Missing three-cell checkpoint 2

The route R1C1 → R1C2 → R1C3 → R2C3 → R2C2 → R2C1 → R3C1 → R3C2 → R3C3 visits all nine cells once. Its consecutive groups each contain three cells. The middle checkpoint total is missing from the record. Which value belongs there? Use the supplied route rather than sorting the board values.

7	17	21
15	22	10
27	20	29

Show the worked answer

A. 47

The relevant cells are R2C3 → R2C2 → R2C1. Their values are 10, 22, 15, which total 47. The other checkpoints do not change where this group starts or ends.

Try next: Circle the three cells before doing the addition, then verify the remaining checkpoints.

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10 / reasoning

Missing three-cell checkpoint 3

The route R1C1 → R2C1 → R2C2 → R1C2 → R1C3 → R2C3 → R3C3 → R3C2 → R3C1 visits all nine cells once. Its consecutive groups each contain three cells. The last checkpoint total is missing from the record. Which value belongs there? Use the supplied route rather than sorting the board values.

14	9	12
3	13	5
17	27	29

Show the worked answer

B. 73

The relevant cells are R3C3 → R3C2 → R3C1. Their values are 29, 27, 17, which total 73. The other checkpoints do not change where this group starts or ends.

Try next: Circle the three cells before doing the addition, then verify the remaining checkpoints.

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11 / reasoning

Missing three-cell checkpoint 4

The route R1C1 → R1C2 → R1C3 → R2C3 → R3C3 → R3C2 → R3C1 → R2C1 → R2C2 visits all nine cells once. Its consecutive groups each contain three cells. The first checkpoint total is missing from the record. Which value belongs there? Use the supplied route rather than sorting the board values.

2	16	22
29	24	9
14	17	4

Show the worked answer

A. 40

The relevant cells are R1C1 → R1C2 → R1C3. Their values are 2, 16, 22, which total 40. The other checkpoints do not change where this group starts or ends.

Try next: Circle the three cells before doing the addition, then verify the remaining checkpoints.

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12 / reasoning

Missing three-cell checkpoint 5

The route R1C1 → R2C1 → R3C1 → R3C2 → R3C3 → R2C3 → R2C2 → R1C2 → R1C3 visits all nine cells once. Its consecutive groups each contain three cells. The middle checkpoint total is missing from the record. Which value belongs there? Use the supplied route rather than sorting the board values.

24	13	17
15	28	27
23	25	3

Show the worked answer

C. 55

The relevant cells are R3C2 → R3C3 → R2C3. Their values are 25, 3, 27, which total 55. The other checkpoints do not change where this group starts or ends.

Try next: Circle the three cells before doing the addition, then verify the remaining checkpoints.

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13 / reasoning

Missing three-cell checkpoint 6

The route R1C1 → R1C2 → R1C3 → R2C3 → R3C3 → R3C2 → R2C2 → R2C1 → R3C1 visits all nine cells once. Its consecutive groups each contain three cells. The last checkpoint total is missing from the record. Which value belongs there? Use the supplied route rather than sorting the board values.

23	15	28
6	20	7
27	12	11

Show the worked answer

A. 53

The relevant cells are R2C2 → R2C1 → R3C1. Their values are 20, 6, 27, which total 53. The other checkpoints do not change where this group starts or ends.

Try next: Circle the three cells before doing the addition, then verify the remaining checkpoints.

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14 / reasoning

Missing three-cell checkpoint 7

The route R1C1 → R1C2 → R1C3 → R2C3 → R3C3 → R3C2 → R2C2 → R2C1 → R3C1 visits all nine cells once. Its consecutive groups each contain three cells. The first checkpoint total is missing from the record. Which value belongs there? Use the supplied route rather than sorting the board values.

26	8	21
19	17	22
10	29	20

Show the worked answer

A. 55

The relevant cells are R1C1 → R1C2 → R1C3. Their values are 26, 8, 21, which total 55. The other checkpoints do not change where this group starts or ends.

Try next: Circle the three cells before doing the addition, then verify the remaining checkpoints.

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15 / reasoning

Three routes, one target record 1

Every proposed route visits this three-row, four-column grid once, using only horizontal or vertical moves. Group each route into consecutive sets of three cells. Which route matches the ordered checkpoint totals 16, 65, 84, 51? A matching grand total alone is insufficient.

4	9	3	34
26	31	25	20
13	12	28	11

Show the worked answer

B. R1C1 → R1C2 → R1C3 → R1C4 → R2C4 → R3C4 → R3C3 → R2C3 → R2C2 → R3C2 → R3C1 → R2C1

All routes use the same cells, so their grand totals agree. The selected route produces 16, 65, 84, 51. The alternative ordered records are 16, 65, 53, 82 and 16, 79, 70, 51.

Try next: Compare the first differing checkpoint to eliminate a route without recomputing every total.

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16 / reasoning

Three routes, one target record 2

Every proposed route visits this three-row, four-column grid once, using only horizontal or vertical moves. Group each route into consecutive sets of three cells. Which route matches the ordered checkpoint totals 66, 64, 32, 57? A matching grand total alone is insufficient.

34	10	22	27
24	31	2	16
20	8	4	21

Show the worked answer

A. R1C1 → R1C2 → R1C3 → R1C4 → R2C4 → R3C4 → R3C3 → R3C2 → R3C1 → R2C1 → R2C2 → R2C3

All routes use the same cells, so their grand totals agree. The selected route produces 66, 64, 32, 57. The alternative ordered records are 66, 64, 37, 52 and 66, 45, 75, 33.

Try next: Compare the first differing checkpoint to eliminate a route without recomputing every total.

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17 / reasoning

Three routes, one target record 3

Every proposed route visits this three-row, four-column grid once, using only horizontal or vertical moves. Group each route into consecutive sets of three cells. Which route matches the ordered checkpoint totals 82, 53, 69, 31? A matching grand total alone is insufficient.

32	28	22	10
6	34	30	13
29	16	14	1

Show the worked answer

A. R1C1 → R1C2 → R1C3 → R1C4 → R2C4 → R2C3 → R2C2 → R2C1 → R3C1 → R3C2 → R3C3 → R3C4

All routes use the same cells, so their grand totals agree. The selected route produces 82, 53, 69, 31. The alternative ordered records are 82, 24, 78, 51 and 82, 24, 59, 70.

Try next: Compare the first differing checkpoint to eliminate a route without recomputing every total.

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18 / reasoning

Three routes, one target record 4

Every proposed route visits this three-row, four-column grid once, using only horizontal or vertical moves. Group each route into consecutive sets of three cells. Which route matches the ordered checkpoint totals 52, 58, 26, 49? A matching grand total alone is insufficient.

27	13	12	8
7	14	11	30
32	10	1	20

Show the worked answer

B. R1C1 → R1C2 → R1C3 → R1C4 → R2C4 → R3C4 → R3C3 → R2C3 → R2C2 → R3C2 → R3C1 → R2C1

All routes use the same cells, so their grand totals agree. The selected route produces 52, 58, 26, 49. The alternative ordered records are 52, 58, 43, 32 and 52, 49, 53, 31.

Try next: Compare the first differing checkpoint to eliminate a route without recomputing every total.

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19 / reasoning

Three routes, one target record 5

Every proposed route visits this three-row, four-column grid once, using only horizontal or vertical moves. Group each route into consecutive sets of three cells. Which route matches the ordered checkpoint totals 68, 34, 49, 92? A matching grand total alone is insufficient.

10	24	34	12
29	33	30	16
18	27	4	6

Show the worked answer

A. R1C1 → R1C2 → R1C3 → R1C4 → R2C4 → R3C4 → R3C3 → R3C2 → R3C1 → R2C1 → R2C2 → R2C3

All routes use the same cells, so their grand totals agree. The selected route produces 68, 34, 49, 92. The alternative ordered records are 68, 34, 67, 74 and 68, 58, 80, 37.

Try next: Compare the first differing checkpoint to eliminate a route without recomputing every total.

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20 / reasoning

Three routes, one target record 6

Every proposed route visits this three-row, four-column grid once, using only horizontal or vertical moves. Group each route into consecutive sets of three cells. Which route matches the ordered checkpoint totals 64, 49, 17, 81? A matching grand total alone is insufficient.

18	32	14	24
10	4	13	12
3	33	28	20

Show the worked answer

C. R1C1 → R1C2 → R1C3 → R1C4 → R2C4 → R2C3 → R2C2 → R2C1 → R3C1 → R3C2 → R3C3 → R3C4

All routes use the same cells, so their grand totals agree. The selected route produces 64, 49, 17, 81. The alternative ordered records are 64, 56, 45, 46 and 64, 56, 64, 27.

Try next: Compare the first differing checkpoint to eliminate a route without recomputing every total.

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21 / reasoning

Three routes, one target record 7

Every proposed route visits this three-row, four-column grid once, using only horizontal or vertical moves. Group each route into consecutive sets of three cells. Which route matches the ordered checkpoint totals 40, 70, 64, 62? A matching grand total alone is insufficient.

13	18	9	22
25	29	19	33
14	23	16	15

Show the worked answer

A. R1C1 → R1C2 → R1C3 → R1C4 → R2C4 → R3C4 → R3C3 → R2C3 → R2C2 → R3C2 → R3C1 → R2C1

All routes use the same cells, so their grand totals agree. The selected route produces 40, 70, 64, 62. The alternative ordered records are 40, 70, 53, 73 and 40, 74, 68, 54.

Try next: Compare the first differing checkpoint to eliminate a route without recomputing every total.

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22 / reasoning

Find the first illegal move 1

A copied route reads R1C1 → R1C2 → R1C3 → R2C4 → R1C4 → R3C4 → R4C4 → R4C3 → R3C3 → R2C3 → R2C2 → R3C2 → R4C2 → R4C1 → R3C1 → R2C1. Move 1 connects the first two coordinates, move 2 the next pair, and so on. Every move must share a horizontal or vertical edge. Which numbered move is the first to break that rule? Cell values do not affect adjacency.

12	11	1	6
10	7	15	5
9	16	3	14
8	4	13	2

Show the worked answer

B. Move 3

Move 3 connects R1C3 → R2C4. The row-and-column distance is greater than one, so those cells do not share an edge. Earlier moves meet the adjacency rule; a later error cannot be the first one.

Try next: Mark the two endpoints of the broken move before trying to repair the route.

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23 / reasoning

Find the first illegal move 2

A copied route reads R1C1 → R1C2 → R1C3 → R1C4 → R3C4 → R2C4 → R4C4 → R4C3 → R3C3 → R2C3 → R2C2 → R2C1 → R3C1 → R3C2 → R4C2 → R4C1. Move 1 connects the first two coordinates, move 2 the next pair, and so on. Every move must share a horizontal or vertical edge. Which numbered move is the first to break that rule? Cell values do not affect adjacency.

1	15	9	5
12	7	6	16
13	4	8	2
14	11	10	3

Show the worked answer

C. Move 4

Move 4 connects R1C4 → R3C4. The row-and-column distance is greater than one, so those cells do not share an edge. Earlier moves meet the adjacency rule; a later error cannot be the first one.

Try next: Mark the two endpoints of the broken move before trying to repair the route.

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24 / reasoning

Find the first illegal move 3

A copied route reads R1C1 → R1C2 → R1C3 → R1C4 → R2C4 → R4C4 → R3C4 → R4C3 → R3C3 → R2C3 → R2C2 → R2C1 → R3C1 → R4C1 → R4C2 → R3C2. Move 1 connects the first two coordinates, move 2 the next pair, and so on. Every move must share a horizontal or vertical edge. Which numbered move is the first to break that rule? Cell values do not affect adjacency.

16	15	11	7
8	13	1	3
6	10	2	12
4	9	5	14

Show the worked answer

A. Move 5

Move 5 connects R2C4 → R4C4. The row-and-column distance is greater than one, so those cells do not share an edge. Earlier moves meet the adjacency rule; a later error cannot be the first one.

Try next: Mark the two endpoints of the broken move before trying to repair the route.

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25 / reasoning

Find the first illegal move 4

A copied route reads R1C1 → R1C2 → R1C3 → R1C4 → R2C4 → R3C4 → R4C3 → R4C4 → R3C3 → R3C2 → R4C2 → R4C1 → R3C1 → R2C1 → R2C2 → R2C3. Move 1 connects the first two coordinates, move 2 the next pair, and so on. Every move must share a horizontal or vertical edge. Which numbered move is the first to break that rule? Cell values do not affect adjacency.

14	3	12	5
1	2	13	16
8	7	4	10
11	6	9	15

Show the worked answer

B. Move 6

Move 6 connects R3C4 → R4C3. The row-and-column distance is greater than one, so those cells do not share an edge. Earlier moves meet the adjacency rule; a later error cannot be the first one.

Try next: Mark the two endpoints of the broken move before trying to repair the route.

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26 / reasoning

Find the first illegal move 5

A copied route reads R1C1 → R1C2 → R1C3 → R1C4 → R2C4 → R3C4 → R4C4 → R4C2 → R4C3 → R3C2 → R3C3 → R2C3 → R2C2 → R2C1 → R3C1 → R4C1. Move 1 connects the first two coordinates, move 2 the next pair, and so on. Every move must share a horizontal or vertical edge. Which numbered move is the first to break that rule? Cell values do not affect adjacency.

9	16	2	3
5	12	10	14
4	15	1	11
7	8	6	13

Show the worked answer

A. Move 7

Move 7 connects R4C4 → R4C2. The row-and-column distance is greater than one, so those cells do not share an edge. Earlier moves meet the adjacency rule; a later error cannot be the first one.

Try next: Mark the two endpoints of the broken move before trying to repair the route.

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27 / reasoning

Find the first illegal move 6

A copied route reads R1C1 → R1C2 → R1C3 → R1C4 → R2C4 → R3C4 → R4C4 → R4C3 → R4C1 → R4C2 → R3C1 → R2C1 → R2C2 → R2C3 → R3C3 → R3C2. Move 1 connects the first two coordinates, move 2 the next pair, and so on. Every move must share a horizontal or vertical edge. Which numbered move is the first to break that rule? Cell values do not affect adjacency.

1	5	13	9
12	11	7	8
3	4	15	14
10	16	6	2

Show the worked answer

B. Move 8

Move 8 connects R4C3 → R4C1. The row-and-column distance is greater than one, so those cells do not share an edge. Earlier moves meet the adjacency rule; a later error cannot be the first one.

Try next: Mark the two endpoints of the broken move before trying to repair the route.

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28 / reasoning

Find the first illegal move 7

A copied route reads R1C1 → R1C2 → R1C3 → R1C4 → R2C4 → R3C4 → R4C4 → R4C3 → R4C2 → R3C1 → R4C1 → R2C1 → R2C2 → R3C2 → R3C3 → R2C3. Move 1 connects the first two coordinates, move 2 the next pair, and so on. Every move must share a horizontal or vertical edge. Which numbered move is the first to break that rule? Cell values do not affect adjacency.

13	8	3	16
5	11	7	14
4	2	6	1
10	15	12	9

Show the worked answer

A. Move 9

Move 9 connects R4C2 → R3C1. The row-and-column distance is greater than one, so those cells do not share an edge. Earlier moves meet the adjacency rule; a later error cannot be the first one.

Try next: Mark the two endpoints of the broken move before trying to repair the route.

Link to this question