What is a fraction?
A fraction shows part of a whole. In 3/4, the bottom number (4) tells how many equal parts there are, and the top number (3) tells how many parts we take.
Key idea
Same bottom number? Just add or subtract the top numbers. 1/4 + 2/4 = 3/4. The bottom stays the same.
Equivalent fractions
Different fractions can show the same amount. ½ is the same as 2/4 and 3/6 — they all fill half.
Worked example
A pizza has 8 equal slices. You eat 3 slices.
Fraction eaten = 3/8.
Fraction left = 8/8 − 3/8 = 5/8.
Comparing fractions
With the same bottom number, the bigger top number is bigger. So 3/4 > 1/4.
To make an equivalent fraction, multiply the top and bottom by the same number. For example, 1/2 = (1×2)/(2×2) = 2/4. The value does not change, only the way it is written.
A whole is written as a fraction when the top and bottom are equal, like 4/4 = 1. This helps when we subtract from a whole, such as 4/4 − 1/4 = 3/4.
Remember
- Bottom = number of equal parts.
- Top = parts taken.
- Add/subtract tops when bottoms match.