Explain how to use long multiplication to multiply two 2-digit numbers regrouping ones to tens | Maths

Starter quiz

Look at the grid model for 31 × 33 shown. 33 has been partitioned into…

32 and 9

30 and 30

30 and 3 ✓

3 and 3
Look at the part-part-whole model. The multiplication equation is:

35 × 7

35 × 72

35 × 27 ✓

35 × 207
Which of these part-part-whole models represents 552 × 17
Calculate 245 × 3 = ______ using short multiplication.

'735' ✓
Calculate 645 × 7 = ______ using short multiplication.

'4,515' ✓
Class 6 at Oak Academy has 227 sheets of stickers. Each page has 5 stickers. How many stickers do they have altogether? ______ stickers

'1,135' ✓

Exit quiz

When using the long multiplication layout the __________ number usually goes at the top.

larger ✓

smaller
Look at the long multiplication layout below. What are the highlighted numbers in the box known as?

Quotients

Addends

Products

Partial products ✓
Look at the long multiplication. Complete it to calculate the product.

'2,782' ✓
Match the expressions to the correct amount of regrouping.

11 × 13

⇔

No regrouping ✓

23 × 14

⇔

1 regroup from ones to tens ✓
Use long multiplication to calculate. A football match is selling tickets at £24 It sells 24 tickets on Monday. How much money was made on Monday? £______

'576' ✓
Use long multiplication to calculate. A football match is selling tickets at £24 It sells 116 tickets on Monday. How much money was made altogether? £______

'2,784' ✓

Worksheet

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Lesson Details

Key learning points

Partition one of the factors.
Calculate the partial products.
Add the partial products to recombine.

Common misconception

Pupils forget to include regrouped values when multiplying.

Decide on a place and structure for regrouped values - they are included at the top of the algorithm in these lessons to avoid confusion with addition regrouping when partial products are summed. Ensure this is clearly modelled.

Keywords

Partial product - Any of the multiplication results we get leading up to an overall multiplication result is a partial product.