Show:
Addition
Subtraction
Patterns
Mystery
100

2 + 8

10

100

12 - 7

5

100

12, 22, __, 42, 52

32

100
What's the missing number? 

18, 21, __, 27, 30

24

200

4 + 10

14

200

20 - 8

12

200

20, 25, 30, __, 40, 

35

200

16 + 12

28
300

10 + 12

22

300

29 - 7

22

300
42, 44, 46, __, 50

48

300

40 - 21

19

400

21 + 15

36
400

38 - 12

26

400

50, __, 56, 59, 62

53

400

12 + 15

27

500

25 + 25

50

500

50 - 25

25

500

18, __, 30, 36, 42

24

500
What's the missing number? 


30, 25, 20, __, 10

15