Multiplying bigger numbers is a matter of breaking them into friendly pieces. Year 5 children multiply by 10, 100 and 1,000, then multiply two- and three-digit numbers by one digit.
What your child will learn
- Multiply whole numbers by 10, 100 and 1,000
- Split a number into hundreds, tens and ones to multiply it
- Multiply a two- or three-digit number by a single digit
Split, multiply, add
To work out 47 × 6, split 47 into 40 and 7. Then 40 × 6 = 240 and 7 × 6 = 42, and 240 + 42 = 282. Multiplying by 10 moves every digit one place to the left — it is not just “adding a zero”, which stops working with decimals.
Example questions
Here are a few questions like the ones in the first quest. Can you solve them?
1. What is 20 × 100?
- 120
- 2000
- 20000
- 200
Show answer
Answer: 2000. Multiplying by 100 moves every digit 2 places to the left. 20 × 100 = 2000.
2. What is 45 × 10?
- 45
- 450
- 55
- 4500
Show answer
Answer: 450. Multiplying by 10 moves every digit 1 place to the left. 45 × 10 = 450.
3. What is 52 × 100?
- 52000
- 152
- 5200
- 520
Show answer
Answer: 5200. Multiplying by 100 moves every digit 2 places to the left. 52 × 100 = 5200.
Tips for grown-ups
- Estimate first: 47 × 6 is a bit less than 50 × 6 = 300.
- Use prices: “6 tickets at 47 each — how much altogether?”