a) 45 - 24 = 21 ; 17 + 10 = 27
→ 45 - 24 < 17 + 10
24 + 35 = 59; 56 - 36 = 20
→ 24 + 35 > 56 - 36
6 + 4 = 10; 7 + 2 = 9
→ 6 + 4 > 7 + 2
b) 32 + 16 = 48; 20 + 28 = 48
→ 32 + 16 = 20 + 28
37 - 17 = 20; 56 - 36 = 20
→ 37 - 17 = 56 - 36
10 - 2 =8; 10 - 1 = 9
→ 10 - 2 < 10 - 1