问题
解答题
用简便方法计算.
48×15
38×62+38×138
840÷12
540÷45.
答案
(1)48×15
=8×6×15
=8×(6×15)
=8×90
=720
(2)38×62+38×138
=38×(62+138)
=38×200
=7600
(3)840÷12
=840÷4÷3
=210÷3
=70
(4)540÷45
=540÷9÷5
=60÷5
=12
用简便方法计算.
48×15
38×62+38×138
840÷12
540÷45.
(1)48×15
=8×6×15
=8×(6×15)
=8×90
=720
(2)38×62+38×138
=38×(62+138)
=38×200
=7600
(3)840÷12
=840÷4÷3
=210÷3
=70
(4)540÷45
=540÷9÷5
=60÷5
=12