Functional Skills: Multiplication

When to Multiply

You can recognise questions that require multiplication in two ways:

1. Questions that use the word “multiply” or “times“, or similar words like “multiplication“.
2. Questions that use the times sign, \times.

Method 2: Grid Method

Multiplying on a Calculator

The above methods are for multiplying without a calculator. Multiplying with a calculator is much simpler. You press each digit individually for the first number, then the times symbol which looks like this: \times, then each digit individually for the second number, then equals.

Example: Multiply 23 and 571 using a calculator.

Press 2 then 3 then \times then 5 then 7 then 1 then =

You should see a result of 13133.

Multiplying by \boldsymbol{10}, \boldsymbol{100} and \boldsymbol{1000}

• To multiply by \textcolor{red}{\boldsymbol{10}}, you move the decimal point one place to the right.
• To multiply by \textcolor{red}{\boldsymbol{100}}, you move the decimal point two places to the right.
• To multiply by \textcolor{red}{\boldsymbol{1000}}, you move the decimal point three places to the right.

This rule can be used for multiplying by 10000, 100000..., just move the decimal point to the right the same amount as the amount of zeros after the 1.

Remember: For whole numbers the decimal point doesn’t look like it’s there, but it is. For example 25 can be written as 25.0

Square Numbers

Multiplying a number by itself is called squaring a number, for instance 6 squared =6\times6=36

Often squared numbers are written using a small 2 – e.g. 6^2

For more difficult squares, like 19^2, if you don’t have a calculator you may have to use the multiplication methods described above, or break the multiplication down into smaller chunks.