Number Snake 🐍

Free interactive math game: Number Snake 🐍 — Winding chain. Part of the Missing Numbers (Gaps) category on MathKite.

Example problems

Taken from the generator that powers this exercise. A fresh set appears every time the page is opened, and the printable worksheet holds ten of them.

  1. What number goes in the gap? 10 +6 → 16 +8 → 24 -6 → ? -8 → 10
  2. What number goes in the gap? 21 -5 → ? +8 → 24 -4 → 20 +5 → 25 +3 → 28
  3. What number goes in the gap? 12 +7 → 19 -4 → 15 -4 → ? +2 → 13 -5 → 8
  4. What number goes in the gap? 9 -4 → 5 +5 → 10 -3 → ? +6 → 13

About this exercise

Following a chain of operations to find a value hidden in the middle.

How to solve it

Move along the chain from a known value, applying each operation as you meet it. To move backwards through the chain, reverse the operation.

Worked example

If a link says +4 and the box after it holds 10, the box before it holds 10 - 4 = 6.

Common mistake

Applying the operation in the direction you happen to be reading. Going against the arrows means undoing, not repeating.