Dividing whole numbers by decimals (hundredths) - ice cream

0:00- [Instructor] We're told at Scoops, each ice cream scoop cost 75 cents. One day, Scoops made $150 selling ice cream scoops. How many scoops of ice cream were sold? Pause this video and have a go at that before we do it together. So, you might have realized, if I take the total amount they made, if I take the $150, and if I were to divide it by how much did they get per scoop, that's that 75 cents right over there, or I could say 75/100 of a dollar.

0:36This will give us the number of scoops sold. So, it really just boils down to how do we divide 150 by 75 or $150 by 75 cents, or we could say 150 by 75/100. One way to do that is to write both of them in terms of hundredths. So, let's just remind ourselves, if I have one whole that is equal to 100/100.

1:09Another way that we could actually do it is we could write everything in terms of cents. Actually, let me do it that way too. I could say one is equal to 100 cents. So, we could use the word hundredths or we could use the word cents. Maybe cents, and we'll make a little more sense, 'cause we, no pun intended, because we're dealing with money here.

1:26So, how many cents is in $150? Well, it's gonna be 100 times as many cents. So, if you have $150, add two zeros there, and that is going to be 15,000 cents. And once again, I could have written hundreds here instead of cents, but I'm now going to divide that into groups of 75 cents.

1:58This is 75/100 or 75 cents. Let me do that in the same color. I'm having trouble switching colors. 75 cents right over here. And that's exactly actually what we are thinking about. I got a total of 15,000 cents, 75 cents at a time. How many times do I need to get 75 cents to get to 15,000 cents?

2:20So, it really just boils down to 15,000 divided by 75. And so, let me set that up over here, 15,000. Write a little bit smaller, just to make sure I have the space, divided by 75. Well, 75 doesn't go into one or 15, but it does go into 150 exactly two times. Two times 75 is 150.

2:47And so, when you subtract, you get a zero here. And I could keep bringing zeros down and dividing, but it's just going to end up being 200. Another way to think about it, 75 goes into 150 two times, but it goes into 150 times 100, 200 times. I could just keep saying, you know, I could have brought down that zero and says it goes into that zero times, zero times 75 is zero.

3:08You subtract, you get zero, and then you bring down that last zero, it goes into that zero times and you multiply and then you subtract and you have no remainder. But we see that this is 200 times. So, how many scoops did they sell? Well, they sold 200 scoops, and we're done.