This is a finish lesson through teaching and also exercises, mirroring how department can be watched as repeated subtraction. It is meant for third grade.

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Students solve departments by "subtracting" or crossing the end equal-size groups from the full in the visual model, until there is nothing left. Examples display how divisions can be fixed by consistently subtracting the exact same number (the divisor). Often, the is actually easier to include intead that subtract, and also figure out how countless times you will add the number (divisor) until you with the dividend.The lesson also shows how number-line jumps tie in through this concept: us jump backwards native the dividend, making jumps of same size (the dimension being the divisor), till we reach zero. The lesson additionally has several word difficulties to solve.

 MULTIPLICATION has to do with plenty of groups of the exact same size.Here is one team of four. Draw one more group of 4 to the picture.And another group. And also another. And one much more group. | || |

You attracted _____ groups of four. 5 × 4 = 4 + 4 + 4 + 4 + 4 = 20.

 Let"s turning back the process. Begin outwith 20 sticks.Make one group of four. In your mind, “move the away” native the picture. Kind another team of four. Again, “move the away”, or subtract the from the picture.Keep developing groups of four till you have none left.How countless groups did girlfriend make? ______ | | | | | | | || | | | | | | || | | |

20 − 4 − 4 − 4 − 4 − 4 = 0This is repeatedsubtraction. You subtract 4 consistently till you reach zero.Each subtraction is a team of 4. How plenty of groups?_____ How many times did girlfriend subtract? _____That is the answer come thedivision difficulty 20 ÷ 4. 1. Make groups, but in your mind "move lock away" orsubtract. Write a individually sentence.

 a. 45 ÷ 15 45 − 15 − ____− ____ = 0 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | b. 56 ÷ 14 56 − 14 − ____ −
 department can be solved by repeated subtraction: 20 ÷ 4 = ?? 20 − 4 − 4 − 4 − 4 − 4 = 0.I subtracted 4 five times, for this reason 20 ÷ 4 = 5. 75 ÷ 25 = ?? 7 5 − 2 5 1 5 0 − 2 5 1 2 5 − 2 5 1 0 3

ns subtracted 25 three times, for this reason 75 ÷ 25 = 3. 84 ÷ 21 = ??

8 4 − 2 1
 1 6 3 − 2 1 1 4 2 − 2 1 1 2 1 − 2 1 1 0 4

ns subtracted 21 4 times, for this reason 84 ÷ 21 = 4 Often, the is handier to actually include instead ofsubtract:

 Since 13 + 13 = 26, 13 goes right into 26 two times. So, 26 ÷ 13 = 2 Since 25 + 25 + 25 = 75, 25 goes into 75 three times. So, 75 ÷ 25 = 3 Since 21 + 21 + 21 + 21 = 84, 21 goes right into 84 four times. So 84 ÷ 21 = 4

2.Write a multiplication sentence and a department sentence the fitsthe addition/subtraction facts.

 a. 5 + 5 + 5 = 1515 − 5 − 5 − 5 = 0 ___ × ___ = ___________ ÷ ___ =____ b. 20 + 20 + 20 + 20 + 20 = _______ − 20 − 20 − 20 − 20 − 20 = 0 ___ × ___ = _________ ÷ ___ =___ c. 23 + 23 + 23 = ________ − 23 − 23 − 23 = 0 ___ × ___ = _________ ÷ ___ =___ d. 14 + 14 + 14 + 14 + 14 = _______ − 14 − 14 − 14 − 14 − 14 = 0 ___ × ___ = _________ ÷ ___ =___
3. Compose a subtraction sentence because that each department sentence.

 a. 45 ÷ 15 = _______45 − b. 32 ÷ 8 = _______32 − c. 100 ÷ 20 = _______100 − d. 50 ÷ 10 = _______50 − e. 50 ÷ 25= _______50 − f. 78 ÷ 26 = _______78 −

 Multiplication is like jumps ~ above the number line. 5 × 4 = 20.Five jumps that 4 it s okay you to 20. Division is favor making jumps of 4 backwards native 20 till you get to 0: 20 ÷ 4 = 5. 20 − 4 − 4 − 4 − 4 − 4 = 0Five jumps of 4 it s okay you native 20 till 0. What department is portrayed here?

4.Draw jumps backwards to highlight the department sentences.

 a. 30 ÷ 5 = _______ b. 16 ÷ 4 = _______ c. 27 ÷ 3 = _______ d. 28 ÷ 4 = _______ e. 42 ÷ 6 = _______ f. 48 ÷ 3 = _______ g. 26 ÷ 2 = _______ h. 39 ÷ 13 = _______ i. 48 ÷ 4 = _______
5. Settle using recurring subtraction OR including up come the number beingdivided.

 a. 40 ÷ 20 = ______90 ÷ 30 = ______30 ÷ 15 = ______ b.52 ÷ 13 = ______34 ÷ 17 = ______69 ÷ 23 = ______ c.88 ÷ 22 = ______32 ÷ 16 = ______72 ÷ 18 = ______ d.45 ÷ 15 = ______90 ÷ 15 = ______90 ÷ 18 = ______

6. If 12 × 2 = 24,then 13 × 2 is _____ . How about division? use the previous trouble to aid you settle the following one.

 a. 24 ÷ 2 = ______26 ÷ 2 = ______28 ÷ 2 = ______30 ÷ 2 = ______ b. 32 ÷ 2 = ______36 ÷ 2 = ______38 ÷ 2 = ______42 ÷ 2 = ______ c. 48 ÷ 2 = ______50 ÷ 2 = ______52 ÷ 2 = ______58 ÷ 2 = ______ d. 60 ÷ 2 = ______66 ÷ 2 = ______70 ÷ 2 = ______78 ÷ 2 = ______
7. Try the same kind of point when dividing by 3.

 a. 30 ÷ 3 = ______36 ÷ 3 = ______39 ÷ 3 = ______ b. 42 ÷ 3 = ______45 ÷ 3 = ______51 ÷ 3 = ______ c. 60 ÷ 3 = ______69 ÷ 3 = ______72 ÷ 3 = ______ d. 81 ÷ 3 = ______90 ÷ 3 = ______99 ÷ 3 = ______
8. Fix the problems.

 a. finish the tables for Alice"s reading schedules, if she reads 12 pages a day Day 1 2 3 4 5 6 7 8 9 10 11 12 Pages read 12 24

she reads 15 pages a job
 Day 1 2 3 4 5 6 7 8 9 10 11 12 Pages read 15 30

she reads 20 pages a day
 Day 1 2 3 4 5 6 7 8 9 10 11 12 Pages read 20 40

If her book has 235 pages and also she wants to review it in two weeks, which reading schedule must she choose?

b. Jerry reads 25 pages a day. How numerous pages go he review in
3 work 5 days 8 work
 10 work 12 work 14 days

c. Jerry"s book has 325 pages. How plenty of days go it take it him to review it? usage the previous practice to help. d. In a bookstore there room many copies of the same publication on the shelf. One book is 2 cm thick. To fill in the table:
Books
 1 2 10 20 30 40 50 60 80 100 Shelf space 2 cm 4 cm

just how many publications can you fit ~ above a shelf 66 centimeter long?

Math Mammoth department 1
A self-teaching worktext for 3rd grade that covers division concept, department & multiplication reality families, native problems, division facts, remainder, zero and one in division, and also more.

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