4.7 Divide Using Partial Quotients

We learned to divide using partial quotients today's lesson was very similar to yesterday's where we started with our dividend and subtract our divisor until we get down to zero. So I could do 184 -8 and then subtract 8 again, 8 again until I get all the way down to zero or I can take some shortcuts by subtracting multiples of 8. So if I subtract 184 -80, that's the same as subtracting ten, 8 because 80 equals ten times 8. Over here, I'm making sure that I'm keeping track of how many times I've subtracted my divisor because that will be my final quotient. So 184 -80 was 104. I have enough that I can subtract 80 again. So that's ten more 8s that I'm subtracting. So I'm keeping track over here that's ten more 8s that I'm subtracting. 104 -80 is 24. And I know that three times 8 equals 24. So if I subtract 24 from 24, that brings me down to zero. And by subtracting 24, that was three more 8. So then the last step to find my quotient is to add how many times I subtracted 8 from 184 to get to zero. So the first time I subtracted 80, that was ten eighths. I did it again. That was ten more. And then finally, when I was at 24, I subtracted three more 8s. So ten plus ten plus three is 23. And then we can always check when we're dividing 23 -8 should equal 184 if I divided correctly. So my quotient times my divisor should equal my dividend. So for number 6, you can start with a really big number like 240. I know that 6 times 40 equals 240. So if I subtract 240. From 258, that's the same as subtracting 40 6s. Then I'm left with only 18 left after I subtract. And I know that three times 6 equals 18. So by subtracting 18 again, I'm subtracting three, 6s. I'm down to zero. So my quotient is 43. So 6 times 43 should equal 258 when I'm checking by multiplying. Another strategy that we learned today was to use a rectangular model. So record the partial products. So this is where we can break our dividend into smaller numbers to make it easier to divide. So I broke 246 into 240 and 6. I know that 240 divided by three is 80. 6 divided by three is two. So 246 divided by three is 82. Down at the bottom, you can choose the strategy for numbers, 7, through 11. Number ten were dividing 112 photos. Into four photos per page and finding how many pages she can film. And number 11, we're doing 726 divided by 6 to find out how much Hector saved each month.