learnbits.app· Geography

Extended tables

You learn the 11, 12, 20, 25 and 50 times tables from a times table you already know.

Practise thisWhiteboardMake it a quiz

How to work it out

  1. Multiply by 11 or 12: do times 10 and add the rest.
  2. Multiply by 20: do times 2 and add a 0.
  3. Multiply by 50: do times 100 and halve it.
  4. Multiply by 25: do times 100 and halve twice.
7 × 117 × 10=707 × 1=770 + 7 = 77

A worked example

11 × 7

  1. Times 11 is times 10 plus one more group.
  2. Do 10 × 7 = 70.
  3. Add one more 7: 70 + 7 = 77.
  4. So 11 × 7 = 77.
More examples

20 × 7

  1. Do 2 × 7 = 14.
  2. Put a 0 on the end: 140.
2 × 7 = 142 × 70 = 140

25 × 8

  1. Do 100 × 8 = 800.
  2. Halve it: 800 ÷ 2 = 400.
  3. Halve it again: 400 ÷ 2 = 200.
8 × 258 × 20=1608 × 5=40160 + 40 = 200

12 × 6

  1. Do 10 × 6 = 60.
  2. Do 2 × 6 = 12.
  3. Add them: 60 + 12 = 72.
6 × 126 × 10=606 × 2=1260 + 12 = 72

Try it yourself

  1. 11 × 9 =

  2. 20 × 4 =

Watch out

  • For times 20 you forget the 0: 20 × 7 becomes 14.

    Times 20 is ten times as much as times 2, so there is always a 0 on the end.

Tips

  • Times 12 is times 10 plus times 2.
  • Think of times 25 as money: four lots of 25 pence make 100 pence.

Why it works

Every big times table looks like a small one. Times 11 is times 10 plus one more group, and times 20 is times 2 with a 0 on the end. Times 50 is half of times 100, and times 25 is half of that again.