Hi! I am Studyfin, your learning buddy. Today we will explore how to add and subtract fractions with different bottom numbers!
Sometimes we want to add fractions like one-half and one-fourth. The bottom numbers, or denominators, are not the same. To add them, we must first make their bottom numbers match.
To make the bottom numbers match, we find a common denominator. We do this by finding a number that both bottom numbers can divide into evenly. For example, both 2 and 4 can go into 4.
Once the bottom numbers are the same, we simply add or subtract the top numbers. The bottom number stays exactly the same in our final answer. Two-fourths plus one-fourth gives us three-fourths!
✏️ Worked example
Solve: 1/2 + 1/3
Look at the bottom numbers, 2 and 3. They are different.
Find a common bottom number. The smallest number both 2 and 3 can multiply into is 6.
Change 1/2 so it has a 6 on the bottom. Multiply the top and bottom by 3 to get 3/6.
Change 1/3 so it has a 6 on the bottom. Multiply the top and bottom by 2 to get 2/6.
Add the top numbers together: 3 + 2 = 5.
Keep the bottom number the same. Your final answer is 5/6!
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