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一、口算。
444 + 56 =
80 - 51 =
97 - 78 =
280 - 75 =
200 - 82 =
85 + 17 =
38 × 20 =
220 - 50 =
702 ÷ 9 =
152 ÷ 8 =
320 × 5 =
312 ÷ 3 =
6900 ÷ 300 =
25 + 266 =
9 × 39 =
63 - 27 =
40 × 34 =
840 ÷ 42 =
490 ÷ 7 =
20 × 56 =
96 + 54 =
960 ÷ 12 =
140 ÷ 5 =
102 × 30 =
444 + 56 =
500
80 - 51 =
29
97 - 78 =
19
280 - 75 =
205
200 - 82 =
118
85 + 17 =
102
38 × 20 =
760
220 - 50 =
170
702 ÷ 9 =
78
152 ÷ 8 =
19
320 × 5 =
1600
312 ÷ 3 =
104
6900 ÷ 300 =
23
25 + 266 =
291
9 × 39 =
351
63 - 27 =
36
40 × 34 =
1360
840 ÷ 42 =
20
490 ÷ 7 =
70
20 × 56 =
1120
96 + 54 =
150
960 ÷ 12 =
80
140 ÷ 5 =
28
102 × 30 =
3060
答案
500 29 19 205 118 102 760 170 78 19 1600 104 23 291 351 36 1360 20 70 1120 150 80 28 3060
二、计算下面各题,怎样简便就怎样计算。
539 - 513 ÷ (378 ÷ 14)
98 × 32
980 ÷ 7 ÷ 7 ÷ 2
(93 + 25 × 21) × 9
[250 - (78 + 82)] × 16
99 × 99 + 99 × 22 + 121
539 - 513 ÷ (378 ÷ 14)
98 × 32
980 ÷ 7 ÷ 7 ÷ 2
(93 + 25 × 21) × 9
[250 - (78 + 82)] × 16
99 × 99 + 99 × 22 + 121
答案
520 3136 10 5562 1440 12100
解析
539 - 513 ÷ (378 ÷ 14)
= 539 - 513 ÷ 27
= 539 - 19
= 520
98 × 32
= (100 - 2) × 32
= 100 × 32 - 2 × 32
= 3200 - 64
= 3136
980 ÷ 7 ÷ 7 ÷ 2
= 980 ÷ (7 × 7 × 2)
= 980 ÷ 98
= 10
(93 + 25 × 21) × 9
= (93 + 525) × 9
= 618 × 9
= 5562
[250 - (78 + 82)] × 16
= [250 - 160] × 16
= 90 × 16
= 1440
99 × 99 + 99 × 22 + 121
= 99 × (99 + 22) + 121
= 99 × 121 + 121
= (99 + 1) × 121
= 100 × 121
= 12100
= 539 - 513 ÷ 27
= 539 - 19
= 520
98 × 32
= (100 - 2) × 32
= 100 × 32 - 2 × 32
= 3200 - 64
= 3136
980 ÷ 7 ÷ 7 ÷ 2
= 980 ÷ (7 × 7 × 2)
= 980 ÷ 98
= 10
(93 + 25 × 21) × 9
= (93 + 525) × 9
= 618 × 9
= 5562
[250 - (78 + 82)] × 16
= [250 - 160] × 16
= 90 × 16
= 1440
99 × 99 + 99 × 22 + 121
= 99 × (99 + 22) + 121
= 99 × 121 + 121
= (99 + 1) × 121
= 100 × 121
= 12100
