Subtracting fractions is similar to adding them, especially when the bottom numbers (denominators) are the same! If you can add fractions, subtracting them will be a breeze. Here's how:
1. Make Sure the Bottom Numbers (Denominators) Are the Same
- Fractions need a "common denominator" to be subtracted easily. If they don't have one, you'll need to find a common denominator.
- Example: If you have 5/8 - 2/8, the denominators are already the same (8)!
2. Subtract the Top Numbers (Numerators)
- Once the denominators are the same, simply subtract the top numbers (numerators).
- Example: 5/8 - 2/8. Subtract 2 from 5, which equals 3. So, 5/8 - 2/8 = 3/8.
3. Keep the Bottom Number (Denominator) the Same
- The denominator stays the same throughout the subtraction. It only tells you how many total pieces there are.
- Example: As we saw above, in 5/8 - 2/8 = 3/8, the denominator remained 8.
4. Simplify (if needed)
- Sometimes, you can make the fraction smaller by simplifying it. This means finding a number that divides evenly into both the top and bottom numbers.
- Example: If you have 4/8, both 4 and 8 can be divided by 4. 4 divided by 4 is 1, and 8 divided by 4 is 2. So, 4/8 simplifies to 1/2.
What if the Bottom Numbers are Different?
This is a little trickier, but still doable!
- Find a Common Denominator: Find a number that both denominators can divide into evenly. Sometimes you can multiply the two denominators together to find a common denominator.
- Adjust the Fractions: You'll need to change the fractions so they both have the common denominator. Whatever you multiply the bottom number by, you must multiply the top number by too!
- Subtract: Now that the denominators are the same, subtract the numerators.
- Simplify: Simplify your answer if possible.
Example: 1/2 - 1/4
- Common Denominator: Both 2 and 4 can divide into 4.
- Adjust Fractions: We need to change 1/2 so it has a denominator of 4. To get from 2 to 4, we multiply by 2. So, we also multiply the top (1) by 2, which gives us 2. So, 1/2 becomes 2/4. The fraction 1/4 already has the right denominator.
- Subtract: 2/4 - 1/4 = 1/4.
- Simplify: 1/4 is already in its simplest form.
So, subtracting fractions is all about making sure those bottom numbers match, subtracting the top numbers, and keeping the bottom number the same!
