Explain how to use long multiplication to multiply a 4-digit by a 2-digit number | Maths

Starter quiz

Match the multiplication expressions to their products.
- 2 × 0.1
  
  ⇔
  
  0.2 ✓
- 0.2 × 10
  
  ⇔
  
  2 ✓
- 12 × 10
  
  ⇔
  
  120 ✓
- 120 × 10
  
  ⇔
  
  1,200 ✓
What is 6,000 × 9 = ______
- '54,000' ✓
What is 700 × 60 = ______
- '42,000' ✓
Complete the long multiplication algorithm to find the product.
- '9,303' ✓
Sam shuffles some cards and arranges them as long multiplication. Use this to calculate the product.
- '4,828' ✓
Sam shuffles some cards and arranges them as long multiplication. Use this to calculate the product.
- '14,202' ✓

Exit quiz

Look at the long multiplication below. The highlighted number is known as the ______.
- 'product' ✓
Complete the long multiplication to find the product.
- '90,712' ✓
The Olympic stadium sells tickets for various events. Each event has 3,145 tickets available, and there are 23 events. How many tickets are sold in total? {{ } tickets
- '72,335' ✓
Each of the 3,414 athletes will receive 22 bottles. How many water bottles are needed in total? ______ bottles
- '75,108' ✓
What is the missing digit in the long multiplication?
- '5' ✓
What is the missing digit in the long multiplication?
- '3' ✓

Worksheet

Loading worksheet ...

Presentation

Loading presentation ...

Lesson Details

Key learning points

Calculate the partial products.
Add the partial products to recombine.
Regroup when numbers bridge 10, 100, 1,000, 10,000

Common misconception

Pupils find it challenging to keep track of multiple regroupings in the long multiplication layout and therefore forget to add these to partial products.

Estimation can support checking of magnitude. Discuss and agree on a position for regrouped values and continuously model noting and using these.

Keywords

Partial product - Any of the multiplication results we get leading up to an overall multiplication result is a partial product.
Regroup - The process of unitising and exchanging between place values is known as regrouping.