Honest Little Apps · Sumbriska browser companion

One bridge changes two totals

Two dated board positions to solve on screen or print. Every bridge sends its whole value to the island its arrow points toward. Flip it and the value moves to its other end.

Try the November 5 position

The upper island starts at 10 and needs 0. The upper-right island starts at 3 and needs 8. The bridge between them is worth 5 and currently points to the upper island. Predict both totals after one flip.

Upper island10Target 0
Upper right3Target 8
Reveal the two totals

Upper island 5, upper-right island 8. The combined total stays 13. One island now matches its target exactly. The upper island still needs to send another 5 away.

Answer. Upper 5, upper-right 8. Together they still total 13.

Test the next decision

Take a separate position from November 4. The left island started at 6 and needed 9. The lower-left island started at 12 and needed 5. A bridge worth 3 pointed to the lower-left island. Which direction should it point now, and what still needs work?

Check the second position

Point the 3 toward the left island. It reaches 9 exactly. The lower-left island falls to 9 and still needs to lose 4. A locally helpful move can bring only one endpoint all the way to its target.

Answer. Point the 3 left. Left reaches 9. Lower left falls to 9, still 4 above target.

Make your own bridge clue

Choose a value from 1 to 9 for the bridge. Give one island enough to send that value away, then choose a starting total for its neighbor. Trade clues with a partner and check whether the combined total stayed the same.

For the puzzle editor

Suggested listing. Sumbriska Daily Bridge Puzzle by Honest Little Apps gives everyone the same five-island board each UTC day. Flip numbered bridges until all five totals match their targets. Yesterday’s board is available, and the browser puzzle opens without sign-in.