Do you know these math problems?

Addition

100

4 + 5

9

200

6 + 6

12

300

17 + 5

22

400

4 + 21

25

500

7 + 6 

13

Subtraction

100

5 - 4

1

200

12 - 4

8

300

24 - 4 

20

400

100 - 99

1

500

4 - 0 

4

Multiplication

100

7 * 2

14

200

5 * 0

0

300

2 * 1

2

400

8 * 8

64

500

8 * 8

64

More Addition

100

15 +5

20

200

13 + 3

16

300

21 + 7

28

400

100  + 100

200

500

500 + 1

501

Something that adds up..

100

something that adds up to 7

1+6 = 7

7 + 0 = 7

5 + 2 = 7

3 + 4 = 7

200

something that adds up to 10

10 + 0 = 10

9 + 1 = 10

5 + 5 = 10

6 + 4 = 10

7 + 2 = 10

300

something that adds up to 20

20 + 0 = 20

15 + 5 = 20

14 + 6 = 20

10 + 10 = 20

400

something that adds up to 100

50 + 50 = 100

100 + 0 = 100

90 + 10 = 100

60 + 40 = 100

500

something that adds up to 15

15 + 0 = 15

10 + 5 = 15

9 + 6 = 15