multiply-divide

基本解释

Simple math tool to practice add, subtra - Simple math tool to practice add, subtract, multiply, and divide.
简单的数学工具用来执行加，减，乘，除运算。
Where they fared less well was number ability (how quickly you can multiply, add, subtract and divide) and perceptual speed - how fast you can push a button when prompted.
年长者表现不太好的方面则是：（数字能力加减乘除运算的速度）以及感知速度——听到指令按下按钮的速度。
So, the number of nuclei, 119 if we were to sit and count these as well, is 119. So, we'll multiply that by just pi, r squared, to get that cross-section, and divide all of that by 1 .
如果你们数的话，原子核的数是，我们用它乘以πr的平方，得到横截面积，除以1。

So, the number of nuclei, 119 if we were to sit and count these as well, is 119. So, we'll multiply that by just pi, r squared, to get that cross-section, and divide all of that by 1 . 39 meters squared.
如果你们数的话，原子核的数是，我们用它乘以πr的平方，得到横截面积，除以1。39平方米。
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