Addition and subtraction

3 digit addition

100

What is 110 + 9?

119

200

What is 421 + 63?

484

300

What is 435 + 15?

450

400

What is 129 + 17?

146

500

What is 346 + 254?

600

2 digit subtraction

100

What is 11 - 5?

6

200

What is 20 - 8

12

300

What is 55 - 23?

32

400

What is 43 - 9?

34

500

What is 75 - 59?

16

3 digit subtraction

100

What is 105 - 5?

100

200

What is 225 - 19?

206

300

What is 456 - 231?

225

400

What is 145 - 56?

89

500

What is 765 - 289?

476

H.E.N decomposition

100

What is 15 in Horizontal Extended Notation?

15 = 10 + 5

200

What is 342 in Horizontal Extended Notation?

342 = 300 + 40 + 2

300

What is 45 + 12 in Horizontal Extended Notation?

45 = 40 + 5

12 = 10 + 2

Answer: 50 + 7

400

What is 245 + 321 in Horizontal Extended Notation?

245 = 200 + 40 + 5

321 = 300 + 20 + 1

Answer: 500 + 60 + 6

500

What is 505 - 231 in Horizontal Extended Notation?

505 = 500 + 00 + 5

- 231 = -200 - 30 - 1

Answer: 200 + 70 + 4