Addition & subtraction

Adding and subtracting 3-digit numbers using mental and written methods

Name:

Date:

Try each question. If you're stuck, leave it and come back. The answer key is on the last page.

1
What is 245 + 130? 245 + 130 = ___
Answer:
2
What is 568 - 200? 568 - 200 = ___
Answer:
3
What is 99 + 99? A) 188 B) 189 C) 198 D) 200
Answer:
4
What is 132 + 145? 132 + 145 = ___
Answer:
5
True or false? 347 + 253 = 600 A) True B) False
Answer:
6
What is 503 - 47? A) 456 B) 466 C) 446 D) 556
Answer:
7
Find the missing number: 260 + ___ = 415 260 + ___ = 415
Answer:
8
Which calculation gives the largest answer? A) 350 + 149 B) 400 + 90 C) 275 + 225 D) 310 + 180
Answer:
9
Sam has 325 stickers. He gives 68 to his friend and then gets 45 more. How many does he have now? 325 - 68 + 45 = ___
Answer:
10
True or false? A book costs £4.50. If you pay with a £10 note, you get £5.50 change. A) True B) False
Answer:

Answer key

Addition & subtraction · for parents and teachers

1
375
200 + 100 = 300, 40 + 30 = 70, 5 + 0 = 5. Total: 375.
2
368
568 - 200 = 368. The tens and ones stay the same.
3
198
99 + 99 = 100 + 100 - 2 = 198.
4
277
100+100=200, 30+40=70, 2+5=7. Total: 277.
5
True
347 + 253: ones 7+3=10 (carry 1), tens 4+5+1=10 (carry 1), hundreds 3+2+1=6. Answer: 600.
6
456
503 - 50 = 453, then 453 + 3 = 456. Or: 503 - 47 = 456.
7
155
415 - 260 = 155. Check: 260 + 155 = 415.
8
275 + 225
350+149=499, 400+90=490, 275+225=500, 310+180=490. The largest is 500.
9
302
325 - 68 = 257. Then 257 + 45 = 302.
10
True
£10.00 - £4.50 = £5.50. Count up: £4.50 + 50p = £5.00, + £5.00 = £10.00.