Equivalent Fractions
Multiply or divide the top and bottom by the same number, and the fraction keeps its value.
Look at the bars below. The top bar shows . The bottom bar shows . They cover exactly the same amount.
That is because is just with the numerator and denominator both multiplied by 2.
The general rule: if you multiply (or divide) the numerator and denominator of a fraction by the same non-zero number, the value of the fraction does not change. We call the results equivalent fractions.
Press "Split each piece" to divide every piece into smaller parts. The fraction label changes but the shaded area stays identical. That is equivalent fractions in action.
Watch it work
Question: Find three fractions equivalent to .
Step 1: Multiply the numerator and denominator by 2.
and ,
so .
Step 2: Multiply the numerator and denominator by 3.
and ,
so .
Step 3: Multiply the numerator and denominator by 4.
and ,
so .
Conclusion: , , and are all equivalent to .
Have a go
Q1. Write two fractions equivalent to .
Multiply numerator and denominator by 2:
.
Multiply numerator and denominator by 3:
.
and (or any other correct pair).
Q2. Are and equivalent? Explain how you know.
Check whether you can multiply the numerator and denominator of
by the same number to get
.
and .
The multiplier is 3 in both cases.
Yes. and are equivalent because and .
Q3. Fill in the blank: .
The denominator has gone from 7 to 21. What was it multiplied by?
, so the multiplier is 3.
Apply the same multiplier to the numerator:
.
The missing number is 6. .
Q4. Marta says and are equivalent. Is she right? Show your working.
Simplify each fraction to its lowest terms.
: divide numerator and denominator by 2
to get .
: divide numerator and denominator by 3
to get .
Yes, Marta is right. Both fractions simplify to , so they are equivalent.