Adding & Subtracting Fractions — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. What is 35 + 45 written as a mixed number?
A) 710
B) 75
C) 125
D) 135
35+45=75. Since 7>5, convert: 7÷5=1 remainder 2, so 75 = 125.
2. What is 514 − 234?
A) 324
B) 224
C) 214
D) 312
Since 14 < 34, borrow 1 from 5: 4 + 114 − 234 = 454 − 234 = 224.
3. A baker used 126 cups of flour in the morning and 256 cups in the afternoon. How much flour in all?
A) 376 cups
B) 416 cups
C) 316 cups
D) 476 cups
1+2=3, 26+56=76=116. Total: 3+116=416 cups.
4. A rope is 638 yards long. You use 478 yards. How much is left?
A) 248 yards
B) 148 yards
C) 1416 yards
D) 238 yards
Since 38 < 78, borrow: 5118 − 478 = 148 yards.
Part B: Fill in the Blank
Write the correct answer on each line.
1. 56 + 56 = 106.
5+5=10, denominator stays 6. Answer: 106 (= 146).
2. 329 + 259 = 579.
3+2=5, 29+59=79. Answer: 579.
3. 413 − 123 = 223.
Borrow 1: 3 + 113 − 123 = 343 − 123 = 223.
4. 712 + 812 = 1512.
7+8=15, denominator stays 12. Answer: 1512 (= 1312).
5. 625 − 345 = 235.
Borrow 1: 5 + 125 − 345 = 575 − 345 = 235.