Number Chains
Keep a running total in your head through a chain of operations. 22 levels, from adding 1 to cube roots.
How Number Chains work
A chain starts with a number, then shows one operation at a time: add 3, double it, take a quarter. Keep a running total in your head and type the number at the end of the chain.
There are 22 levels, from adding 1 and 2 up to percentages, negatives and cube roots. Choose 5, 8, 10 or 15 steps. If you go wrong, Review shows the answer after every step.
Three ways to use it
On the board
Go full screen and reveal one step at a time with Space or → (← goes back), or let Auto timer set the pace. Students show their final answer on mini-whiteboards, then Review walks through every step.
On paper
Print gives three chains from that level at the length you have chosen, with a box for each step. The answers are on page 2.
Against the clock
Challenge shows the whole chain at once. Type each answer and see how many you can get right in 1, 2 or 3 minutes, with your best streak at the end.
Choose a level
Set how the chain runs, then pick a level. Each card shows a short chain from that level. Every level also mixes in adding and subtracting.
Beginner
Levels 1 to 4+1, +2, −1 and −2
Add up to 5, subtract up to 4, double
Double and halve
Add up to 9, subtract up to 7, double, halve
Foundations
Levels 5 to 8×10 and ÷10, double, halve
×2, ×3, ÷2, ÷3, double, halve
×2 and ×5, double, halve
×2 to ×5, ÷2 and ÷3, double, halve
Tables
Levels 9 to 12×2 to ×5, ÷2 to ÷5, double, halve
÷2 to ÷10, ×2 to ×5, double, halve
×2 to ×12, ÷2 to ÷6, double, halve
×2 to ×12 (not 7, 9 or 11), ÷2 to ÷6, ÷10
Fractions
Levels 13 to 15½ and ¼ of, ×2 to ×4, ÷2 to ÷4
½, ⅓, ¼ and ⅕ of, ×2 to ×5, ÷2 to ÷5
½, ⅔, ¾ and ⅗ of, ×2 to ×5, ÷2 to ÷5
Percentages and powers
Levels 16 to 18Square it, square root, ½ of, ×2 to ×5, ÷2 to ÷5
50%, 25% and 10% of, ×2 to ×4, ÷2, ÷4, ÷5, ÷10
⅔ and ¾ of, 50%, 25%, 20% and 10% of
Expert
Levels 19 to 22×(−1), square it, square root, ×2 to ×5, ÷2 to ÷5
Cube root, ×(−1), ⅗ and ⅝ of, 15% and 75% of, squares and roots
Squares and roots, ½, ⅓ and ¼ of, 50%, 25% and 10% of, × and ÷ up to 12
Everything: cube roots, ×(−1), ⅔, ¾, ⅗ and ⅝ of, 15% to 75% of