 # 8.09 Order and compare volume

Lesson

## Ideas

Remembering how to  order numbers  can help us in this lesson. Let's try this problem to practice.

### Examples

#### Example 1

Order these numbers from smallest to largest.

516, \, 156, \, 561

Worked Solution
Create a strategy

We should order the hundreds first, then the tens, then the ones.

Apply the idea

The numbers in the place value table are shown:

156 has the smallest hundreds digit so it is the smallest number.

516 and 561 have equal hundreds digits, but 516 has the smaller tens digit.

The numbers from smallest to largest are: 156,\,516,\, 561

Idea summary

We can put numbers in order using a place value table and comparing the digits from the highest place value.

## Order and compare volumes with unit cubes

Let's see how we can use unit cubes to compare the volumes of different 3D shapes.

### Examples

#### Example 2

We want to compare the volumes of the following block stacks.

Which block stack has the smaller volume?

A
B
Worked Solution
Create a strategy

Count and compare the number of blocks in each stack.

Apply the idea

We can see that option A is made up of 8 blocks and option B is made up of 9 blocks. Since 8 is smaller than 9, option A has the smaller volume.

Idea summary

Volume means how much space our shape takes up. We can compare volumes by comparing the number of blocks of space the objects take up.

## Compare volume by numbers

In this video, we see how we can compare the numbers, to work out the largest volume, as long as our shapes are using the same unit of measurement.

### Examples

#### Example 3

Select the correct symbol to compare the following two numbers:

95 \text{cm}^3 ⬚ 98 \text{cm}^3

A
\lt
B
\gt
Worked Solution
Create a strategy

Use a number line to compare the two numbers.

Apply the idea

Plot the two numbers.

If we look at the number line above, we can see that 95 is smaller than 98 as it is further to the left on the number line. So: 95 \lt 98

The correct symbol is option A.

Idea summary

If we have shapes with the same unit of measurement, we can compare the numbers, to work out the largest volume.

### Outcomes

#### MA2-11MG

measures, records, compares and estimates volumes and capacities using litres, millilitres and cubic centimetres