Grade 1: Missing addend - sums with 20
The number of all possible operations is equal to 42
Solve.

________ + 15 = 20

________ + 10 = 20

________ + 5 = 20

________ + 13 = 20

________ + 2 = 20

________ + 7 = 20

________ + 16 = 20

________ + 19 = 20

________ + 0 = 20

________ + 14 = 20

________ + 11 = 20

________ + 6 = 20

________ + 17 = 20

________ + 3 = 20

________ + 4 = 20

________ + 18 = 20

________ + 8 = 20

________ + 12 = 20

________ + 1 = 20

________ + 9 = 20

________ + 20 = 20

5 + ________ = 20

6 + ________ = 20

4 + ________ = 20

18 + ________ = 20

16 + ________ = 20

7 + ________ = 20

15 + ________ = 20

2 + ________ = 20

11 + ________ = 20

19 + ________ = 20

3 + ________ = 20

1 + ________ = 20

0 + ________ = 20

20 + ________ = 20

12 + ________ = 20

8 + ________ = 20

14 + ________ = 20

9 + ________ = 20

17 + ________ = 20

13 + ________ = 20

10 + ________ = 20




Grade 1: Missing addend - sums with 20
The number of all possible operations is equal to 42
The Answer.

5 + 15 = 20

10 + 10 = 20

15 + 5 = 20

7 + 13 = 20

18 + 2 = 20

13 + 7 = 20

4 + 16 = 20

1 + 19 = 20

20 + 0 = 20

6 + 14 = 20

9 + 11 = 20

14 + 6 = 20

3 + 17 = 20

17 + 3 = 20

16 + 4 = 20

2 + 18 = 20

12 + 8 = 20

8 + 12 = 20

19 + 1 = 20

11 + 9 = 20

0 + 20 = 20

5 + 15 = 20

6 + 14 = 20

4 + 16 = 20

18 + 2 = 20

16 + 4 = 20

7 + 13 = 20

15 + 5 = 20

2 + 18 = 20

11 + 9 = 20

19 + 1 = 20

3 + 17 = 20

1 + 19 = 20

0 + 20 = 20

20 + 0 = 20

12 + 8 = 20

8 + 12 = 20

14 + 6 = 20

9 + 11 = 20

17 + 3 = 20

13 + 7 = 20

10 + 10 = 20