Question

二十道简便运算题

Answer 1

(1)101×99
=(100+1)×99
=100×99+99
=9999
(2)14×35
=7×2×35
=7×70
=490
(3)25×28
=25×4×7
=100×7
=700
(4)4×9×25
=4×25×9
=100×9
=900
(5)43×5×4
=43×20
=860
(6)15×12
=15×2×6
=30×6
=180

追答

(7)12×(40-5)
=12×40-12×5
=480-60
=420

(8)64×9-14×9
=(64-14)×9
=50×9
=450

(9)35×98
=35×(100-2)
=35×100-35×2
=3500-70
=3430

(10)23×134-34×23
=23×(134-34)
=23×100
=2300

Answer 2

（1）80✘5✘6
=80✘30
=2400
（2）（25+12）✘4
=25✘4+12✘4
=100+48
=148
（3）45✘5✘10
=（45✘10）✘5
=450✘5
=2250
（4）58+79+42
=（58+42）+79
=100+79
=179

Answer 3

（46+28）60=74X60=4440
42X50-17=2083
32+105/5=32+21=53
42OX（327一238）=420x89=37380

Answer 4

375+219+381+225
5001－247－1021－232
（181+2564）+2719
378+44+114+242+222
276+228+353+219
(375+1034)+(966+125)

Answer 5

135×35-35×35
=35×（135-35）
=35×100
=3500