四年级5道简便运算

Question

四年级5道简便运算

Answer 1

472+503
=472+500+3
=972+3
=975

143+(57+26)
=143+57+26
=200+26
=226

78-46-14
=78-(46+14)
=78-60
=18

32×125
=4×8×125
=4×(8×125)
=4×1000
=4000

38×29+38
=38×(29+1)
=38×30
=1140