Question

25×28有哪四种简便计算方法

Answer 1

第一种：假设法。
25x28
=25x30-25x2
=750-50
=700
第二种：因式分解法
25x28
=25x（4x7）
=(25x4)x7
=100x7
=700
第三种：假设法的另一种运用
25x28
=28x30-28x5
=840-140
=700
第三种：因式分解法的另一种运用
25x28
=28x（5x5）
=(28x5)x5
=140x5
=700

Answer 2

25x28
=25x4x7
=100x7
=700
25x28
=28x100/4
=2800/4
=700
25x28
=25x30-25x2
=750-50
=700
25x28
=28x30-28x5
=840-140
=700

Answer 3

25X(20十8)
=25X20十25X8
=500十20O
=700

Answer 4

25x28 =25x30-25x2 =750-50 =700

Answer 5

25x28
=25x4x7
=100x7
=700