帮我算几道题 （要用简便方法） 13.2-3.7-6.3 10.26-（3.78+4.26） 101*7.8 1/5*24+176x20% 32*12.5*0.25

13.2-3.7-6.3
=13.2-(3.7+6.3)
=13.2-10
=3.2

10.26-(3.78+4.26)
=10.26-4.26-3.78
=6-3.78
=2.22

101×7.8
=(100+1)×7.8
=100×7.8+1×7.8
=780+7.8
=787.8

1/5×24+176×20℅
=24×1/5+176×1/5
=(24+176)×1/5
=200×1/5
=40

32×12.5×0.25
=4×8×12.5×0.25
=(4×0.25)×(8×12.5)
=1×100
=100

13.2-3.7-6.3 10.26-(3.78+4.26)
=13.2-(3.7+6.3) =10.26-4.26-3.78

=13.2-10 =6-3.78

=3.2 = 2.22
一个数连续减去两个数等于减去这两个数的和。

101×7.8 拆分法
=(100+1)×7.8 乘法分配率
=100×7.8+1×7.8
=780+7.8
=787.8

1/5×24+176×20℅
=24×1/5+176×1/5
=(24+176)×1/5
=200×1/5
=40

32×12.5×0.25
=4×8×12.5×0.25
=(4×0.25)×(8×12.5)
=1×100
=100

13.2-3.7-6.3=13.2-(3.7+6.3)=13.2-10=3.2
10.26-（3.78+4.26)=6-3.78=2.22