26 + 7 = 26 + 4 + 3 = 30 + 3 = 33
38 + 4 = 38 + 2 + 2 = 40 + 2 = 42
42 + 9 = 42 + 8 + 1 = 50 + 1 = 51
60 − 38 = 60 − 30 − 8 = 30 − 8 = 22
70 − 27 = 70 − 20 − 7 = 50 − 7 = 43
80 − 16 = 80 − 10 − 6 = 70 − 6 = 64
14 = 1 дес. 4 ед.
40 = 4 дес. 0 ед.
19 = 1 дес. 9 ед.