Вычислите устно:
а) 35 + 5 = 40;
59 + 1 = 60;
87 + 3 = 90;
44 + 6 = 50;
28 + 12 = 40;
б) 43 – 6 = 37;
30 – 1 = 29;
51 – 4 = 47;
27 – 8 = 19;
24 – 7 = 17;
в) 6 \(\cdot\) 7 = 42;
9 \(\cdot\) 4 = 36;
8 \(\cdot\) 8 = 64;
5 \(\cdot\) 9 = 45;
9 \(\cdot\) 6 = 54;
г) 64 \(\cdot\) 10 = 640;
50 : 10 = 5;
70 \(\cdot\) 10 = 700;
100 : 100 = 1;
100 \(\cdot\) 100 = 10000;
д) 72 : 9 = 8;
48 : 6 = 8;
56 : 7 = 8;
81 : 9 = 9;
40 : 8 = 5.