一个正方体棱长扩大2倍,它的体积也扩大2倍. .
将分数1写成两个数相除的式子:1 .
:16=15÷ == %= (填小数)
÷ = :16=5÷ = %=0.25.
0.8=12÷ = :10= %
÷ =8﹕ = ﹕15==.