# Significant figures

## Home learning focus

In today's lesson, you will learn about significant figures and how to estimate.

This lesson includes:

• a learning summary
• two videos
• two activities

Created in partnership with Sparx.

# Learn

Significant figures show how important each digit in a number is when you want to know its size.

## Significant figures - integers

For integers, identify the significant figures from left to right.

When rounding a number to a significant figure, you end up with an approximate value for the number. This can be useful when estimating the answers to difficult calculations.

Now, watch this video from Sparx to find out how to round integers to a given significant figure.

## Significant figures - decimals

Rounding decimals to a given significant figure is very similar to rounding integers, but there is one important difference.

For decimals, leading zeros are not significant.

Watch this video from Sparx to find out how to round decimals to one or two significant figures.

# Practise

## Activity 1

Significant figures - Integers

Have a go at this worksheet from Sparx on rounding integers to one or two significant figures. You can print it out or write your answers on a piece of paper.

## Activity 2

Significant figures - Decimals

Have a go at this worksheet from Sparx on rounding decimals to one or two significant figures. You can print it out or write your answers on a piece of paper.

# There's more to learn

Have a look at these other resources around the BBC and the web.