Understand fractions

The whole comes first. A fraction only makes sense when you know what one whole represents.

Your learning goal

Represent a fraction as equal parts, a number on a line and a division.

Understand the idea

Name the whole before the part

Three quarters of a small bottle and three quarters of a large bottle describe the same proportion, but different volumes. When comparing amounts, keep the whole and its units consistent. A diagram must show equal-sized parts, not just the right number of regions.

Words worth knowing
Numerator
The number of equal-sized parts being counted.
Denominator
The number of equal-sized parts in one whole; it cannot be zero.
Unit fraction
One equal part of a whole, such as 1/5.
Fraction of a set
A fraction of a collection of objects, with the whole collection as the reference.
Make it visible

Name the whole. Count the equal parts.

Predict a result, change a value, and use the diagram to explain your reasoning.

Choose a fraction

Predict before changing a value. Every whole in a bar diagram uses the same size. The models use non-negative amounts up to two wholes per input.

Read the fraction as a count of unit fractions

In 3/5, one whole contains five equal fifths and you count three of them. The numerator counts; the denominator names the unit. More parts in the whole means each part is smaller. Five fifths make one whole.

A fraction is also a number and a division

The number 3/4 is the point three quarter-steps from zero. It is also 3 ÷ 4: sharing three identical whole items equally among four people gives each person three quarters of one item. A fraction can be zero, equal to one or greater than one.

A set can be the whole

If 3 of 12 counters are blue, the fraction blue is 3/12 = 1/4. The denominator counts all counters, not only the counters of the other colour. To find 3/4 of 12 counters, split 12 into four equal groups and take three groups: 9 counters.

Follow the reasoning

One decision at a time.

Work out the next step before opening the explanation.

Read 7/4 on a number line
  1. Each step is 1/4 of the same whole.
  2. Four quarter-steps reach 1. Three more reach 7/4.
  3. 7/4 = 1 3/4. An improper fraction is a valid way to name this number.
Share 3 litres equally among 4 containers
  1. The total is 3 L; the number of equal groups is 4.
  2. Each share is 3 ÷ 4 = 3/4 L.
  3. Check: 4 × 3/4 L = 3 L. The shares use all the liquid.
Try with support

Make your thinking visible.

Use paper or a whiteboard. Show the equal parts, calculation and explanation before comparing your response.

A ribbon is cut into 8 equal pieces. You use 3 pieces. What fraction of the original ribbon is used?

Give me a hint

Count the pieces used and the equal pieces in one original ribbon.

Compare a worked response

3/8

The numerator is 3 pieces; 8 pieces make the original whole.

A class has 24 students; 6 walk to school. What fraction walk?

Give me a hint

The whole set is all 24 students. Simplify the fraction.

Compare a worked response

6/24 = 1/4

Six of 24 students is one of four equal-sized groups.

Independent practice

Build a strategy you can explain.

Fresh questions · useful feedback

Build fluency, one decision at a time.

Work through eight questions. Two independent correct answers introduce a harder version; supported answers bring the next question back to the foundation. You can use hints at any time.

0 of 8 questions completed

Use an exact fraction (7/12), mixed number (1 3/4), or terminating decimal. For comparisons use <, = or >. Follow any requested form; leave units out of the answer box.

This round saves on this device. It is practice, not a school mark.

Check the concepts, too.

1. Which diagram could represent 2/3 of a whole?

2. What does 5/5 represent?

3. How much is 3/4 of 20 counters?

Make it matter

What does the answer mean?

A bottle marked 3/4 full tells you a proportion. Its capacity tells you the actual volume. Both pieces of information matter.

Choose your next connection.

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