# Writing decimals

## Home learning focus

Learn how to write decimals using place value columns.

This lesson includes:

• one learning summary
• four interactive activities

# Learn

### Decimals in daily life

Decimals are all around you:

• They are used to write amounts of money (£1.99).
• You see them when baking or on packets of food to show weight (1.5 kg of flour).
• They’re used in length (1.45 km).
• Even time uses decimals (10.15 seconds).

That is why it is important to understand how to write decimals and understand their place value.

### Tenths and hundredths

We use a decimal point to separate the whole from the parts of a whole.

• When one whole is divided into 10 parts, you call it a tenth.

• When one whole is divided into 100 parts, you call it a hundredth.

You often see tenths and hundredths written as fractions, for example ⁹¹/₁₀₀.

Have a look at last week's lessons on tenths and hundredths for a reminder.

The place value columns for tenths and hundredths look like this:

Let's look at how you write decimals.

### Example 1

How would you write thirteen and fifty-two hundredths as a decimal?

Use your knowledge of place value and partitioning. Thirteen is made up of one ten and three ones.

There are fifty-two hundredths. This is made up of 5 tenths and 2 hundredths. These numbers go after the decimal point.

So thirteen and fifty-two hundredths is written 13.52

### Example 2

Write ²¹/₁₀₀ as a decimal.

Use your knowledge of place value: ²¹/₁₀₀ (21 hundredths) is made up of 2 tenths and 1 hundredth.

In a place value chart that would look like this:

There are no ones, so you write zero in the ones column to show this!

If you have no ones at all, you must write a zero before the decimal point. This is to show that it is a number smaller than one.

# Practise

## Activity 1

Rearrange the numbers into the correct place value columns.

## Activity 2

Writing decimals

Answer the questions on the worksheet below from Twinkl - can you get them all right?

## Activity 3

Decimals and measurement

Look at the worksheet below from Whizz Education. Write down your answers to the questions about decimals in measurement.

Remember, 1 cm = 10 mm

Check here for the answer sheet

## Activity 4

Guardians: Defenders of Mathematicia

Play the Palace of Place Value level in Guardians: Defenders of Mathematicia to test your knowlege of decimals and place value.

# There's more to learn

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