Comparing Fractions
We compare fractions to determine which one is greater or which one is less. We may have two fractions and we want to determine which one is bigger. We may have several fractions and want to put the fractions on a number line. We may want to determine if a fraction is greater than 1.
We can compare fractions in two ways with like denominators (denominators are the same)
or with unlike denominators (denominators are different). The second one is more challenging.
Comparing Fractions with like denominators
3/5 compared to 4/5
The denominators are the same meaning the size of the parts are the same. To compare these we simply look at the numerators and determine which one is greater. In this case the 4 is greater than the 3 so 4/5 is greater.
It also means that 4/5 is closer to 1 than th 3/5 is.
Comparing Fractions with unlike denominators
2/3 compared to 4/5
1. In this case it is difficult to determine which fraction is greater so we need to draw a model to decide which one is bigger.
By looking at the fractions as a picture we can see that 4/5 is greater than 2/3.
2. We can also compare fractions by finding common denominators.
To find common denominators we need find a number they can both be multiplied by.
2/3 compared to 4/5
2 x 5 = 10 4 x 3 = 12
3 x 5 15 5 x 3 15
I multiplied the numerator and the denominator by the same number and got a new fraction or what we refer to as an equivalent fraction.
Now I can compare the two fractions and say that 12/15 is greater than 10/15.
Try This!
- Choose 6 fractions less than 1 and place them on a number line. How did you decide where they belonged on the number line?
2. Choose 6 fractions that are greater than 1 place them on a number line. How did you decide where they belonged on the number line?
3. Was it easier or harder to put the fractions that were less than one on the number line or the numbers that were greater than 1. Explain why?
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