课后 • 练习第2题答案
637– 263– 337 42x250x4
=637– 337– 263 =42x(250x4)
=300– 263 =42x1000
=37 =42000
99x28=28 48x125
=(99+1)x28 =125x8x6
=100x28 =1000x6
=2800 =6000
3700÷4÷25 28x15+72x15
=3700÷(4x25) =(28+72)x15
=3700÷100 =100x15
=37 =1500
6300÷(63x5) 450÷18
=6300÷63÷5 =450÷9÷2
=100÷5 =50÷2
=20 =25
课后 • 练习第3题答案
300÷12=300÷3÷4=25(kg)
答:平均每个箱子里装25kg山楂。
课后 • 练习第4题答案
8700÷(25x4)=87(个)
87<90,够用。
答:90个盒子够用。
课后 • 练习第5题答案
(1)36x111+888x8
=36x111+111x8x8
=111x(36+8x8)
=11100
(2)99x999+199
=99x999+99+100
=99x1000+100
=99100