2.3

Within 10

LEVEL ONE

3; 3; 6

1; 3; 7

9

9; 6; 3

5; 2; 1; 8

11

13

15

17

12

LEVEL TWO

- ; + ; +

LEVEL THREE

8; 2; 6 or 8; 6; 2

1; 8; 9 or 8; 1; 9

9; 4; 5 or 9; 5; 4

third

fourth

2; 3; 5 or 3; 2; 5

6; 2; 4

6; 4; 2

0; 4; 4

10; 4; 6

3; 7; 10 or 7; 3; 10

10; 3; 7 or 10; 7; 3 

10-2-2

2+3=5
8-1=7

3; 8

6; 5 or 3; 2

5+1=6
7-3=4

5; 10