考點:整數(shù)四則混合運算
專題:運算順序及法則
分析:(1)先算減法,再算除法,最后算乘法;
(2)先算乘法,再算除法,最后算加法;
(3)先算小括號里面的減法,再算除法,再算中括號里面的減法,最后算乘法;
(4)先算減法,再算除法,再算加法,最后算乘法;
(5)先算除法,再算減法,最后算乘法;
(6)先算乘法,再算除法,最后算減法.
解答:
解:(1)630÷(21-12)×16
=630÷9×16
=70×16
=1120;
(2)530+54×4÷8
=530+216÷8
=530+27
=557;
(3)[150-3÷(30-28)]×10
=[150-3÷2]×10
=[150-1.5]×10
=148.5×10
=1485;
(4)[48÷(75-69)+24]×15
=[48÷6+24]×15
=[8+24]×15
=32×15
=480;
(5)(630÷9-23)×250
=(70-23)×250
=47×250
=11750;
(6)168-48×16÷8
=168-768÷8
=168-96
=72.
點評:整數(shù)混合運算的關鍵是抓住運算順序,正確按運算順序計算即可.