Visually dividing a whole number by a decimal
About this video
This video finds 3 ÷ 0.75 by thinking of three wholes in hundredths and asking how many equal groups of 75 hundredths fit inside. A colour-coded picture shows exactly four groups of 75 hundredths, so 3 ÷ 0.75 = 4.
You'll be able to
- think of dividing by a decimal as asking how many equal groups fit.
- use a hundredths model to find 3 ÷ 0.75.
- explain why dividing by a number less than 1 gives a bigger answer.
Key words
- hundredths
- Parts you get by splitting one whole into 100 equal pieces.
- equal groups
- Groups that each have exactly the same amount.
- whole
- One complete thing, like one full square, equal to 100 hundredths.
Transcript
- [Instructor] In this video, we're going to see if we can compute what three divided by 0.75 is equal to, and I'll give you a little bit of a hint before I tell you to pause the video. So let's imagine three wholes right over here, and what if we were to think of these three wholes, these three ones, and what if we were to think about them in terms of hundredths?
Well then we could, once we express these as hundredths, we could say, well how many groups of 75 hundredths can we divide this into? How many equal groups of 75 hundredths? To help you think about that, here's a little bit of a visualization where three is divided into equal groups of 75 hundredths.
So pause this video and use what I have, this little visual here, as a big hint to figure out what three divided by 75/100 is. All right, now let's do it together. So as I said, we started with three ones, or three wholes, however you want to think about it, and you could divide division by 75/100 as saying, well how many equal groups of 75 hundredths can you divide these three wholes into?
And so we thought about these three wholes in terms of hundredths, and the way it's been color coded, it actually has already been divided into four equal groups of 75 hundredths. You can count these, so this is 10, 20, 30, 40, 50, 60, 70, and then five hundredths.
So this right over here, this is one group of 75 hundredths. Then in green you have another group of 75 hundredths. So you have 10, 20, 30, 40, 50, 60, 70, and then 75, so that right over, let me use a color I can see. This right over here is our second group.
This is our first group right over there. Then that's our third group, these are all equal groups of 75 hundredths, and that's our fourth equal group of 75 hundredths in the green again. So how many equal groups of 75 hundredths can you divide three wholes into?
Well, clearly it is equal to four.
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