When we divide a number by another number ($x \div y$), we can interpret it in two ways:
- $x$ is divided in equal groups, where each group consists of $y$
- $x$ is divided in $y$ equal groups
Suppose we divide $500 \div 5$. We can interpret this in two ways:
- $500$ is divided in equal groups of $5$
- $500$ is divided in $5$ equal groups
Now, if we divide $5 \div 500$, how can we interpret it in the same way? I am a beginner at math and I want to understand this in a simple manner on the number line. I would be grateful for your assistance. Thank you
Let's interpret $5\div 500$:
$5$ is divided into $500$ equal groups. Here you need to think of the $5$ as something that is not limited to being an integer. Don't think apples, or people. Maybe kilos of gold, or liters of water, or cups of flour, or something. In that case, it is easier to imagine dividing it up into many small groups, and we see that each group is alotted $5\div 500 = 0.01$.
$5$ is divided into groups, each group containing $500$. This one is, as you say, a little tricky. But it's still doable. You are unable to finish a single group. How much of a group do you get? You get $5\div 500 = 0.01$ of a group.
Maybe interpretation 2 is a little easier to imagine when the numbers are a bit closer. Like, for instance, $5\div 10$. If you try to make groups of 10, and you only have 5 available, it is difficult to dispute that you will get half a group. And one half in decimal is $0.5$. Thus $5\div 10 = 0.5$.
Note that these two interpretations are complementary. If you say that $10\div 5 = 2$ according to one of the interpretations, then you automatically have $10\div 2 = 5$ according to the other interpretation. This is also true for something like $5\div 500 = 0.01$ versus $5\div 0.01 = 500$.