Grade 4 · Unit 1: Number and place value

Written multiplication

Multiply 3-digit numbers and 2-digit by 2-digit.

Bricks for a wall

A truck carries 245 bricks per trip and makes 6 trips. How many bricks? Estimate: 250 × 6 = 1500.

Short multiplication

6 × 5 = 30: write 0, carry 3. 6 × 4 = 24, + 3 = 27: write 7, carry 2. 6 × 2 = 12, + 2 = 14. Answer: 1470.

2-digit × 2-digit: grid

Split both numbers into tens and ones. Multiply each pair. Add all four partial products: 840.

Check it

24 is close to 25. 25 × 35 = 875 (a quarter of 3500). 840 is a little less – it makes sense.

3-digit × 2-digit

Split both numbers and multiply every part. Row 20: 6000 + 800 + 120 = 6920. Row 5: 1500 + 200 + 30 = 1730. Total: 8650. Estimate: 350 × 25 = 8750 ✓

What I learnt

• I can multiply 3-digit by 1-digit numbers.
• I can multiply 2-digit by 2-digit numbers.
• I can estimate to check.