124÷8乘以4怎么巧算 6.3÷1.8巧算

6.3÷1.8巧算  

6.3÷1.8巧算

6.3÷1.8
=6.3÷0.9÷2
=7÷2
=3.5

6.3乘6.3-6.3+6.3乘6.7怎么巧算

=6.3×(6.3-1+6.7)
=6.3×12
=75.6

7.8×0.37 0.78×6.3巧算

7.8×0.37 +0.78×6.3巧算
=7.8×（0.37+0.63）
=7.8×1
=7.8

3.6×6.3-6.3+63×0.74怎么巧算

3.6×6.3-6.3+63×0.74
=3.6×6.3-6.3+6.3×(10×0.74)
=3.6×6.3-6.3+6.3×7.4
=(3.6-1+7.4)×6.3
=10×6.3
=63

6.3×2.7+1.9×21巧算

解：原式=21x0.3x27+1.9x21
=21x8.1+1.9x21
=21x（8.1+1.9）
=21x10
=210
分析：主要考察拆分法和结合律的运用。

6.3÷4.2怎么巧算?

都先除以2.1 就等于3÷2了

1.02×6.3怎么巧算

=（1+0.02）×6.3
=1×6.3+0.02×6.3
=6.3+0.126
=6.426

5.24×163-52.4×6.3巧算

5.24×163-52.4×6.3
=5.24×163-5.24×10×6.3
=5.24×163-5.24×63
=5.24×(163-63)
=5.24×100
=524

6.15×1.8+1.85÷1.8巧算

解：直接运算最简便，
原式=6.15×1.8+1.85÷1.8
≈11.07+1.03
=12.1

6.3×1.7×1.5怎么巧算?

6.3×1.7×1.5=6.3×1.7+6.3×0.85=6.3×2.55=.6.3×2+6.3×0.5+6.3×0.05=12.6+3.15+0.315
=16.065
6.3×1.7×2.5=6.3×3.4+6.3×0.85=6.3×4.25=.6.3×4+6.3×0.2+6.3×0.05=25.2+1.26+0.315
=26.775