Decimals

NZ Level 4

Number lines and decimals (tenths/hundredths)

Lesson

Number lines work the same way, whether we are using decimals or not, with numbers increasing as we move to the right. Getting the hang of a number line with whole numbers is a great way to see how they work. You can also look at number lines using fractions, since fractions are just a different way to express decimals.

When we divide $1$1 unit into 10 equal pieces, it is broken into $10$10 tenths, as shown below.

When we work with decimals, remembering that $0.1$0.1 is $\frac{1}{10}$110 is really helpful. Have a look at how we can plot decimals in tenths in this video.

Next, can you work out what these numbers on a number line are? Instead of plotting decimals, we have to work out what has been plotted for us.

Remember!

$10$10 tenths make $1$1 unit.

When we work with hundredths, the process is the same but the end points on our number line are different. $1$1 tenth is broken into $10$10 hundredths, so we are zooming in on smaller numbers.

Let's plot some hundredths together in this video.

Can you work out what these decimals are? You'll also how to work out which number is furthest to the right on a number line, as well as a special twist for those keen to plot some tricky numbers.

Remember!

$10$10 hundredths make $1$1 tenth.

The larger the number, the further to the right it will be on a number line.

Plot $0.3$0.3 on the number line.

What number is shown on the following number line?

Plot $0.25$0.25 on the number line.

Know the relative size and place value structure of positive and negative integers and decimals to three places.