SIX SMALL PUZZLES / NO TIMER
One part is missing.
Can you see it?
A whole. A known part. One gap to fill. Try six quick puzzles and see why subtraction and addition tell the same story.
Free browser practice. No score ranking, signup or countdown.
Find the part. Check the whole.
Fill the gap
Round 1 of 6
Original browser exercise. This is not the app’s ricochet gameplay or a measured ability test.
TABLETOP PUZZLE
Make-ten link cards
Start with tile F. Match its right number to the left number on the next tile so the two add to 10. Use every tile once and keep them upright. You can cut out the cards or solve by writing their letters in order.
Print the seven link cards and fold-away answer key (one-page PDF)
Read all seven tiles on screen
- Tile A: 9 on the left, 5 on the right.
- Tile B: 4 on the left, 3 on the right.
- Tile C: 3 on the left, end on the right.
- Tile D: 2 on the left, 1 on the right.
- Tile E: 5 on the left, 7 on the right.
- Tile F: start on the left, 6 on the right.
- Tile G: 7 on the left, 8 on the right.
Bonus: If G ends in 4 instead of 8, which number must start D so the new join still makes ten?
Check the chain and bonus answer
F → B → G → D → A → E → C. The joins are 6 + 4, 3 + 7, 8 + 2, 1 + 9, 5 + 5 and 7 + 3. In the bonus, D starts with 6 because 4 + 6 = 10.
MAKE THE RESULT USEFUL
Use the whole to find the gap.
If the whole is 10 and one part is 6, count from 6 up to 10: four steps. That gives both 6 + 4 = 10 and 10 − 6 = 4.
- Say the whole first.
- Look at the part you already know.
- Find what is left, then add the two parts to check.
The later rounds change the whole to 15 and 20. The relationship stays the same.
THE NEXT STEP
Make the numbers move.
In Number Beasts: Bond Lab, numbers become projectiles. Plan bonds, feeds and leftover numbers across puzzle boards. The app includes handcrafted stages and a daily puzzle.
Get Number Beasts on the App Store ↗The current App Store listing says free, no ads and no in-app purchases. Requires iOS 18 or later. Check the listing for current compatibility.
Publisher disclosure: Honest Little Apps publishes Number Beasts and this companion resource. This is not an independent review. App details checked November 4, 2026.
Jump back, then adjust
Use the round number as a stepping stone. First subtract the suggested multiple of ten, then enter a signed adjustment to land on the exact answer.
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