When doing a long multiplication, you must set it out using place value columns, and lining your numbers up carefully.

When dividing two numbers, use the 'bus stop' method where the number you are dividing by is to the left of the bus stop.

It is important to follow BIDMAS during calculations. Always do division and multiplication before addition and subtraction.

Example videos

Video: https://www.youtube.com/embed/FeOZQD3feYg

Video: https://www.youtube.com/embed/etAFdcDWKGQ

Video: https://www.youtube.com/embed/wYd9Nt2_8i4

Practice questions

Multiplication and division of whole numbers - questionsMultiplication and division of whole numbers - worked solutions

Multiplication and Division by 10, 100, 1000 etc

Multiplication for whole numbers:

× 10 We add a zero to the end of the number: for example 32 × 10 = 320
× 100 We add two zeroes to the end of the number: for example 4 × 100 = 400

And so on...

Multiplication for decimals:

× 10 We move the decimal point one place to the right so as to make the number bigger: for example 4.51 × 10 = 45.1
× 100 We move the decimal point two places to the right

And so on...

Division for any kind of number (whole number or decimal):

÷ 10 Move the decimal point to the left by one place in the number so as to make it smaller: for example 64.2 ÷ 10 = 6.42
÷ 100 Move the decimal point two places to the left in the number

And so on...

Example videos

Video: https://www.youtube.com/embed/whRtSXOAptU

Video: https://www.youtube.com/embed/KSBUfUHkcLY

Practice questions

Multiplication and division by 10, 100, 1000 etc - questionsMultiplication and division by 10, 100, 1000 etc - worked solutions