巧妙计算题目!小学数学!

来源:百度知道 编辑:UC知道 时间:2024/05/26 02:37:27
9999×7+1111×37

48×1.08+1.2×56.8

18×七分之五-5×七分之四

2.5×2.85+0.25÷二十三分之二

9999×7+1111×37
=9×1111×7+1111×37
=63×1111+1111×37
=(63+37)×1111
=100×1111
=111100

48×1.08+1.2×56.8
=48×1.08+1.2×4×14.2
=48×1.08+4.8×14.2
=48×1.08+48×1.42
=48×(1.08+1.42)
=48×2.5
=12×4×2.5
=12×10
=120

18×七分之五-5×七分之四
=(14+4)×(5/7)-5×(4/7)
=14×5/7+4×5/7-5×4/7
=10+20/7-20/7
=10

2.5×2.85+0.25÷二十三分之二
=2.5×2.85+0.25×23/2
=2.5×2.85+0.25×11.5
=2.5×2.85+2.5×1.15
=2.5×(2.85+1.15)
=2.5×4
=10