Multiplying numbers
Multiplication is fast, repeated addition. 3 × 4 means 4 + 4 + 4 = 12. To multiply bigger numbers, multiply each place value and carry.
Key idea
To multiply, work from the ones and carry tens to the next column. Keep the product below 10 000.
Worked example
Worked example
Work out 123 × 3.
Ones: 3 × 3 = 9
Tens: 2 × 3 = 6
Hundreds: 1 × 3 = 3
So 123 × 3 = 369.
Handy tricks
× 10 adds one zero (25 × 10 = 250). Multiplying by 2 is doubling (45 × 2 = 90).
Remember
- Learn your times tables well.
- Start from the ones and carry.
- × 10 just adds a zero.