Let’s do a few sample questions:
Adding fractions #1, 9
Subtracting fractions #1, 9
Adding fractions #1:
If we need to add or subtract fractions, we need a common denominator (the lower number in a fraction).
So the 10 and 20 are different, so we can’t add them, we can make it the same by muiltying by 2.
remember we need to times both numbers, upper and lower, by the same number.
2*2 = 4
So now we did the math, we will have and .
So we add them, only the upper number, do not touch the number on the bottom.
We can see that can be divided by 5 nicely so we simplity the fraction
5÷5 = 1
20÷5 = 4
Now we down the math, the final answer is .
Adding fractions #9:
Okay, if we follow the same steps shown above, it will be very easy. But first, we need to get rid of the whole number wich is the 4 and 5.
4+5 = 9
Okay, now we have the whole number added up together, we can do the addition of the fractions.
We need to make the lower number the same, so we know 3*4 =12 right? Then we can time the second fraction by 3.
1*3 = 3
4* 3 = 12
So when we did the math, the fraction will be .
Now we can add them. Do not change the number at the bottom.
8+3 = 11
So the fraction will be . It can not be simplified so we leave it that way. DO NOT FORGET ABOUT THE WHOLE NUMBER.
9 + = .
We put the whole number back in, so the final answer is .
Subtracting fractions #1:
We know we can’t subtract or add without the number at the bottom is different, so we need to make it the same. And we know 4*7=28 so we can times the first fraction by 7.
3*7 = 21
So now we have .
Now we subtract, but don’t touch the number on the bottom.
21- 11 = 10
So we have . We can see the fraction can be divided by 2 nicely. So we divide both number, upper and lower, by 2.
10 ÷ 2= 5
28÷ 2= 14
So we have as the final answer.
Subtracting fractions #9:
First we subtract the whole numbers, 5 and 2. Then we can deal with the fractions.
Now we can subtract the fractions, and we need make the numbers on the bottom the same. We know 3*4 = 12, so we time the second fraction by 4.
So now we have . Then we can do the substraction.
So now we have . And it can be simplified by 2 so we divide the fraction by 2.
So our final answer is .
I did the sample questions for you, and I hope you can try the rest. Please remember a few highlights:
1. Need common denominator when ADDING or SUBSTRACTING
2. Do not change the denominator when you are ADDING or SUBTRACTING
3. Change the denominator when you are MUTIPLING OR DIVIDING
4. Always SIMPLIFY the fractions.
Hope this can help you! Please give me the brainliest answer if you like it! If you have any questions please leave a comment or add me as a friend!