Eureka Math Grade 4 Module 3 Lesson 32

all right this is fourth grade module 3 lesson 32 and in this student we're going to be practicing our students are going to be practicing that standard algorithm for division they're going to be dividing by 6 7 8 and and the real point of this lesson is to have students practice reading the problem and then drawing the model that that problem represents so that students can begin making the connection between the model or the drawing and the the word problem lot of teachers are always saying my students have hard time with word problems so this lesson is really going to focus on giving the students an opportunity to understand the word problem so that they can model it appropriately all right for these problems I'm going to show the tape diagram for all of the problems but I'm only going to solve the actual division problem for couple of them so let's get started man bought package of 435 party favors to give to the guests at her birthday party and she calculated that she could give nine party favors to each guest how many guests is she expecting so what is that tape diagram going to look like well we're going to start with bar and that entire bar represents the 435 party favors and we want to know she knows she's going to give nine party favors to each guest so that means we've got nine right here then we've got nine right here then we've got nine right here and we are going to keep going 9999999 until we have reached all the way to 435 so the big question is how many nines are there going to to and now this represents nice this is kind of basically tape diagram representing division and so now we could divide so will actually divide 435 / 9 and so we've got 400s divided amongst nine groups you can't do that so we're going to think about 431 divided amongst nine groups and 4310 divided amongst nine groups means there's going to be four tens in each of those groups that gives us 36 tens and we're going to subtract and we end up with let's see seven tens left over then we're going to bring down that five because now we have 7 plus 5 1es so now we have 75 ones being divided amongst the nine groups so that means eight each group gets eight ones or eight units so that's 72 we have three units left over so our answer is 48 with remainder of three so what does that mean that means if we're going to Define this and represent this that means we're going to have 48 nines 48 NES 489 and this remainder of three means we're going to have three party favors I'm trying to draw party favor here three party favors left over three favors left over all right and that's what that means so she's expecting 48 guests and she knows that she's going to have three party favors left over so this one I'm just going to draw the tape diagram I'm not going to solve the division problem but we have 4,000 pencils were donated to an elementary school if eight classrooms shared the pencils equally how many pencils did each class receive you know what I'm actually going to divide am going to do this one because this is the other kind of division problem so this is called partitive because we know that there's eight parts there's eight classrooms so the whole tape diagram is 4,000 pencils and we know we're going to divide that up into eight groups and now we know how many groups it's eight and that's why wanted to do this one the other problem the previous problem we didn't know how many groups we just knew that each group had nine this time we we know that there's eight groups groups eight classrooms and the the question is how big is each classroom or each group how many pencils are in each classroom so let's do it so we've got 4,000 divided 8 4,000 four thousands divided amongst eight groups you can't do so we're going to think of this as 40 hundreds and 40 hundreds divided amongst eight groups means each group gets five that means we have nothing left over and so we have no no tens no hund no units so the answer is 500 and sure enough if you know if we wanted to check our math we could do 500 time 8 and then 8 * 5 is 40 plus bring these two extra zeros down so there's our 4,000 so we know we did it right and we know that each classroom gets 500 pencils and there is no remainder so the remainder is zero so that means there are no pencils left over so each classroom gets 500 pencils here is where I'm just going to draw the model so we've got 2,8 kilogram of potatoes were packed into sacks so here is our 28 potatoes kilograms of potatoes and they're they're packed into sacks weighing 8 kilog each how many sacks were packed so that means here's 8 kg here's 8 kg here's 8 kilg etc etc etc and the question is how many of these 8 kilograms are we going to have so there's our question mark right there so the proper division is going to be 2,8 ided eight and that gives us the division problem that's going to tell us how many sacks are packed Baker made Seven batches of muffins and there was total of 252 muffins if there was the same number of muffins in each of those seven batches how many muffins were in batch so the idea is here is our muffins this is our total number of muffins so it's 252 muffins and we know that there's seven batches so that means we can cut that into seven groups one 2 3 four five six seven because that each one of these groups or each one of these units represents batch of muffin and the question is how many muffins is in one batch so what's our division problem our division problem is going to be ided 7 and parents and teachers I'm going to leave it up to you to show the division because the important thing right here is what should the tape diagram look like and the last problem we have some and she ran 3,3 in 7 days if she ran the same distance each day how far did Samantha run in three days that's little bit of trick isn't it so we're going to start by drawing the tape diagram and the tape diagram represents the that she did in seven days so we know that we need to cut this in into seven Parts 1 2 3 4 5 6 seven parts and the idea is each one of those represents day so that equals one day so the division is going to be 33 / 7 but here's the thing that only gives us the answer for one day right here one day but the question is how how about three days so once you got that answer for one day you then have to multiply or add repeatedly and get the answer for three days so you're going to have to take get your answer which is for one day and then multiply by three to get three days and that wraps up let's see fourth grade module 3 lesson 32 students are practicing division but really the important thing is they're dividing and they're mean they're modeling what the division looks like and they're either dividing where they are they know the number of parts and their job is to figure out one part or they know that the whole and let's just stick with 252 and they're they're being told well there's how many fours let's say how many fours so we know the size of each GR group and the question is how many groups are there so those are the two different kinds teachers this is called partitive because we know how many parts and this is called measure measurement where you know the size of each group and you're just trying to figure out how many groups there are hav