How to play math pyramid puzzles

Every brick is the sum of the two touching it from below. Fill every blank while keeping the printed numbers in place.

A small example

Going up: 4 + 3 = 7, and 3 + 3 = 6. The top is 7 + 6 = 13.

Working down: if the middle-left brick is 7 and the brick below-right is 3, the missing lower-left brick is 7 − 3 = 4.

You can repeat numbers. There is no Sudoku rule about rows or columns. Every answer here is a whole number from 1 to 40.

Make your first entry

1. Choose a blank brick. Its neighbouring trio is highlighted.
2. Find a trio with two known numbers. Add the lower two, or subtract one lower number from the number above.
3. Type the answer in the Number field or use the digit buttons, then choose Place.

A marked trio means its three numbers do not add up. Clear brick removes your selected entry. Undo takes back one entry, hint or restart.

Hints and keyboard controls

Hint corrects a wrong entry first. When two correct neighbours are visible, it shows the addition or subtraction used. If those neighbours are not yet known, it clears the wrong entry and shows the trio to revisit. With no errors, it fills a brick you can calculate from two known neighbours.

On the pyramid, use arrow keys to move between bricks. Type a digit to start an answer, then press Enter to place it. Delete or Backspace clears an entered brick. In the Number field, Escape cancels your draft.

Daily and practice

There are 24 puzzles: twelve with 3 layers and twelve with 4. Daily uses a 12-day rotation based on UTC. A saved daily board stays on its original date until you choose Play today. That action replaces both daily sizes; practice stays separate.

Practice selects from the same collection. Your two practice sizes and two daily sizes save separately in this browser. If storage fails, a notice explains what is kept and how to retry.