某乡今年修了5条水渠,总长5000米,正好等于去年修的4倍,去年比今年少修多少米?
算一算,填一填. 3×8÷4 = ÷ = 72÷9÷2 = ÷ = 6×8+15 = + = .
脱式计算: (1)408÷4×5 = = (2)(548﹣233)÷5 = = .
递等式计算: (15+25)×8 (49+21)×(84÷12) 205﹣135÷9.
口算. 100﹣43= 56÷14= 18×5= 630÷70= 550÷5= 69÷3= 14×30= 24+86= 60×80= 960÷80= 180×30= 720÷60= 750÷50= 17×50= 450÷90= 36×20=
用你喜欢的方法脱式计算. (1)128+750÷25×18 (2)(800×﹣360)÷40 (3)×+× (4)[1﹣(﹣)]×.