• Mastery PD Materials

## Multiplication strategies for larger numbers and long multiplication

Spine 2: Multiplication and Division – Topic 2.23

### Introduction

Develop strategies for multiplying two numbers with two or more digits, including adjusting strategies when multiplying by a power of ten, partitioning followed by multiplication and addition of partial products, and long multiplication.

### Teaching points

• Teaching point 1: When multiplying two numbers that are multiples of 10, 100 or 1,000, multiply the number of tens, hundreds or thousands and then adjust the product using place value.

• Teaching point 2: When multiplying two numbers where one number is a multiple of 10, 100 or 1,000, use short multiplication and adjust the product using place value.

• Teaching point 3: Two two-digit numbers can be multiplied by partitioning one of the factors, calculating partial products and then adding these partial products. This method can be extended to multiplication of three-digit numbers by two-digit numbers.

• Teaching point 4: 'Long multiplication' is an algorithm involving multiplication, then addition of partial products, which supports multiplication of two numbers with two or more digits.

• Teaching point 5: Multplication where one of the factors is a composite number can be carried out by multiplying one factor and then the other factor.

• Primary
• KS2
• Year 6