Round Decimals and Mixed Numbers Revision | KS3 Maths Resources

## What you need to know

Things to remember:

• Think about the numbers the mixed number is between.
• If the fraction is one half or more, the whole number parts goes up by 1.
• If the fraction is less than one half, the whole number part rounds down.

Round $2\dfrac{5}{8}$ to the nearest whole number.

When we think about rounding, we are looking at numbers close to the number we’re rounding. Here, we’re rounding the mixed number $2\dfrac{5}{8}$, so what is it between? Well, our whole number part is 2, and we’ve add a bit of a whole number to it, so it is somewhere between 2 and 3.

But we can’t really tell where it should be on here, so we need to break it up and check where the fraction gets us to.

Looking at the number line, we can see that our number is closer to 3 than 2, so $2\dfrac{5}{8}$ rounded to the nearest whole number is 3.

It is important to notice the fraction in the middle, that doesn’t look like the others… $\dfrac{1}{2}$. Our fraction was after this, so we rounded up. This gives us our rule.

Fraction                                                           Rounding

$\dfrac{1}{2}$ or more                     Round up

Less than $\dfrac{1}{2}$                   Round down

Round $6\dfrac{2}{5}$ to the nearest whole number.

$$\frac{2}{5}<\frac{1}{2}$$

Round down.

$6\dfrac{2}{5}$ rounded to the nearest whole number is 6.

Round $1\dfrac{3}{4}$ to the nearest whole number.

$$\frac{3}{4}>\frac{1}{2}$$

Round up.

$1\dfrac{3}{4}$ rounded to the nearest whole number is 2.

## Example Questions

$$\frac{5}{6}>\frac{1}{2}$$

Round up.

$2\frac{5}{6}$ rounded to the nearest whole number is 3.

$$\frac{7}{15}<\frac{1}{2}$$

Round down.

$4\frac{7}{15}$ rounded to the nearest whole number is 4.