0.78×0.78的简便方法

2025-06-28 06:03:54
推荐回答(1个)
回答1:

0.78x0.78
=78x78÷10000
=(80-2)X(80-2)÷10000
=[80x80-2x80x2+2x2]÷10000
=(6400-320+4)÷10000
=6084÷10000
=0.6084

或者0.78x0.78
=(0.8-0.02)X(0.8-0.02)
=[0.8x0.8-2x0.8x0.02+0.02x0.02]
=(0.64-0.032+0.0004)
=0.6084