四年级数学用计算器计算1.ppt

文档介绍：用计算器计算练****br/>算一算
找规律
框一框
读一读
(1) 678+795
(2) 9023-1186
(3) 457×142
(4) 8624÷56
复****用计算器计算
复****用计算器计算
1、比一比,看谁算得又对又快.
34
×357
-9018
÷48
-2922
÷34
×125
3840
12138
3120
65
918
27
3375
练****br/>练****1比一比看谁算得又快又对
2. 用计算器计算.
94×86÷47 (394+5477)÷57
8450÷25-249 6396÷(520-438)
练****2用计算器计算
,并找一找各组的规律。
9 × 9 — 1 =
98 × 9 — 2 =
987 × 9 — 3 =
9876 × 9 — 4 =
× —=
80
880
8880
88880
练****3计算并找规律
9 × 9 — 1 =
98 × 9 — 2 =
987 × 9 — 3 =
9876 × 9 — 4 =
× —=
80
880
8880
88880
练****3计算并找规律
9 × 9 — 1 =
98 × 9 — 2 =
987 × 9 — 3 =
9876 × 9 — 4 =
× —=
80
880
8880
88880
9 × 9 — 1 =
98 × 9 — 2 =
987 × 9 — 3 =
9876 × 9 — 4 =
× —=
80
880
8880
88880
9 × 9 — 1 =
98 × 9 — 2 =
987 × 9 — 3 =
9876 × 9 — 4 =
98765 × 9 — 5 =
987654 × 9 — 6 =
9876543 × 9 — 7 =
98765432 × 9 — 8 =
80
880
8880
88880
888880
8888880
88888880
888888880
总结
19 + 9×9 =
118 + 98×9 =
1117 + 987×9 =
11116 + 9876×9 =
111115 + 98765×9 =
1111114 + 987654×9 =
11111113 + 9876543×9 =
111111112 + 98765432×9 =
100
1000
10000
100000
1000000
10000000
100000000
1000000000
进一步计算找规律1