Adding Fractions
1/2 plus 1/4
3/4
1/2 subtract 2/5
5/10 - 4/10 = 1/10
1.5 plus 1.27
2.77
6.78 subtract 4.3
2.48
How do you change a subtraction problem to an equivalent addition problem?
Keep the first term, Change the subtraction sign to an addition sign, Change the second term to positive/negative.
3/4 plus 3/8
6/8+3/8 =9/8 or 1 1/8
1/10 - 1/3
3/30 - 10/30
10-3=7 so the answer is -7/30
2.789 + 1.1234
3.9124
6.22 subtract 4.333
1.887
How do you add 2 terms with the same sign?
7/8 + 1/3
21/24 + 8/24 = 29/24 or 1 5/24
-4/5 subtract -3/5
-4/5 plus 3/5
4-3=1 so the answer is -1/5
12.7 plus -4.9
12.7 - 4.9 = 7.8
4.44 subtract -3.333
4.44 plus 3.333 = 7.773
How do you add 2 terms with different signs?
Subtract them and keep the sign of the one there was more of (positive and negatives cancel each other out).
-2/5 plus -1/4
-8/20 + (-5/20) = -13/20
2/5 subtract -3/6
12/30 - (-15/30)
12/30 + 15/30 = 27/30
-12.72 plus -4.9
12.72 + 4.9 = 17.62
so the answer is -17.62
-3.45 subtract -1.5
-3.45 plus 1.5
3.45 -1.5 = 1.95 so the answer is -1.95
How do you add/subtract decimals?
Put the larger absolute value on top and be sure to line up the decimal place. Then subtract starting at the right and borrowing from the left as necessary.
-2/5 plus 1/4
-8/20 plus 5/20
8-5=3 so the answer is -3/20
-2/3 subtract -3/5
-2/3 + 3/5
-10/15 + 9/15
10-9=1 so the answer is -1/15
-12.43 plus 5.888
-6.542
-123.4 - 4.321
-123.4 plus -4.321
123.4 + 4.321 =127.721 so the answer is -127.721
How do you add/subtract fractions?
Find the Least Common Multiple of the denominators and use equivalent fractions to get fractions with common denominators, then keep the denominator and add/subtract the numerators.