Visually dividing decimal by whole number

In this video, we're going to try to figure out what 4 tenths divided by 5 is. So pause this video and see if you can think about it before we work through it together. We're really going to think about approaching this visually.

All right, now let's work through this together and let's actually try to think about what 4 tenths looks like. So, if you view this entire square as a whole, you see that we've divided it into 10 equal columns or 10 equal sections, and four of those tenths are shaded in. So what you see here in blue is four tenths.

But how do we divide that into five and make sense of it? Well, one way to think about it is to imagine four tenths not just as four tenths, but to imagine it as forty hundredths. So this would be imagining it as forty hundredths. So we can rewrite four tenths divided by five as 40 hundredths divided by 5.

And now we could think about taking these 40 hundredths—each of these little squares is a hundredth—and divide it into five equal sections. And then we could say, well, how many hundredths are in each of those five equal sections? So let's do that.

So let's see, this is one, this is two, this is three, this is four, and then we have five equal sections. So how many hundredths are in each of those equal sections? Well, we can see in each of them you have one, two, three, four, five, six, seven, eight.

So, forty hundredths divided by five is going to be eight hundredths, because we have eight of these little squares in each of those five equal sections. So, eight hundredths we would write like this.

And so, forty hundredths divided by five is eight hundredths. Then, four tenths divided by five is also equal to eight hundredths.