Long Division With 2 Digit Divisor

1
Long DivisionWith 2 Digit Divisor
2
Lesson Essential Questions

• Why use division?
• What are the steps for dividing?
• How do you solve real-world problems using
  division?

3
Key Vocabulary

• Dividend
• Divisor
• Quotient
• remainder

4
Dividend

• The amount to be divided

• 36 9 4
• 36 is the dividend

5
Divisor

• The number used to divide by

• 36 9 4
• 9 is the divisor.

6
Quotient

• The answer when one number is divided by another.

• 36 9 4
• 4 is the quotient.

7
Remainder

• The amount left over when one number can not be
  divided exactly by another.

• 17 7 2 R 3
• 3 is the remainder

8
Why use division?

• To divide an amount of something into groups
• 36 candy pieces to be shared by 4 friends
• 36 4

9
How do we divide whole numbers by 2-digit
divisors?

• DMSBR

10
Long Division With 2 Digit Divisor

• Use our family to help you remember the steps in
  long division.

Dad
Mom
Sister
Brother
Rover
11
2 Digit Long Division

• Each person represents a step in the long
  division process.

3. Subtract
1. Divide
Sister
4. Bring down
Dad
Brother
2. Multiply
5. Repeat or Remainder
Mom
Rover
12
Step 1 in 2 Digit Long Division
4
1. Divide
2 1) 9 4 8
Dad

• Divide 21 into first number in the dividend.

How many 20s will go into 90?

• 21 will not go into 9 so
• you look at 94.

• Round off 21 and 94 in
• your head.

• Now divide 20 into 90
• put your answer above the 4.

13
Step 2 in 2 Digit Long Division
4
2. Multiply
2 1) 9 4 8
Mom
8
4

• Multiply the divisor times the first number
  in your quotient.

21 x4 84

• Write your answer directly under the 94 or
  the number you just divided into.

14
Step 3 in 2 Digit Long Division
4
3. Subtract
2 1) 9 4 8
Sister
8
4

• Draw a line under the 84.

• Write a subtraction sign next to the 84.

1
0

• Subtract 84 from 94.

• Write your answer directly below the 84.

15
Step 4 in 2 Digit Long Division
4
4. Bring down
2 1) 9 4 8
Brother
8
4

• Go to the next number in the dividend to the
  right of the 4.

1
0
8

• Write an arrow under that
• number.

• Bring the 8 down next to the 10.

16
Step 5 in 2 Digit Long Division
4
5. Repeat or Remainder

2 1) 9 4 8
Rover
8
4

• This is where you decide whether you repeat the
  5 steps of division.

1
0
8

• If your divisor can divide into your new
  number, 108, or if you have numbers in the
  dividend that have not been brought down, you
  repeat the 5 steps of division.

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Step 1 in 2 Digit Long Division
4
5
1. Divide
2 1) 9 4 8
Dad
8
4

• Divide 21 into your
• new number, 108.

1
0
8

• Round 21 and 108 off
• in your head.

• Divide 20 into 110

• Place your answer directly
• above the 8 in your quotient.

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Step 2 in 2 Digit Long Division
4
5
2. Multiply
2 1) 9 4 8
Mom
8
4

• Multiply your divisor, 21, with your new number
  in the quotient, 5.

1
0
8
1
5
0

• Place your answer directly under the 108.

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Step 3 in 2 Digit Long Division
4
5
3. Subtract
2 1) 9 4 8
Sister
8
4

• Draw a line under the bottom number, 105.

0
8
1

• Draw a subtraction sign.

0
1
5

• Subtract place answer under the line.

3

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Step 4 in 2 Digit Long Division
4
5
4. Bring down
2 1) 9 4 8
Brother
8
4

• Since there is nothing to
• bring down, go to step
• five.

0
8
1
0
1
5
3

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Step 5 in 2 Digit Long Division
4
5
R3
5. Repeat or Remainder
2 1) 9 4 8
Rover
8
4

• If the 21 will not divide into your new number,
  3, there is nothing to bring down, you are done.

8
1
0
0
1
5
3

• Write your left over 3 as the
• remainder next to the 5.

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Way to go!
Super work!
4
5
R3
2 1) 9 4 8
8
4
Youre hot!
8
0
1
Im proud of you!
0
1
5
Bow-wow!
3
23
Lets See That again
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Long Division

• Let this family help you remember the steps in
  long division.

Dad Mom Sister Brother Rover
25
Long Division
DMSBR

• Each family member represents a step in solving
  long division problems.

Dad Mom Sister Brother Rover
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Step One - Divide

• Divide 3 into the first number in the dividend.
• 3 will go into 4 one time.
• Write a 1 above the 4 because thats the current
  dividend.

1
3) 497
Dad
27
Step Two - Multiply

• Multiply the divisor times the first number in
  the quotient.
• Write the answer below the number you just
  divided into.

1
3) 497
3
Mom
28
Step Three - Subtract

• Subtract.
• Be sure to line up your numbers carefully.

1
3) 497
3
Sister
1
29
Step Four Bring Down

• Draw an arrow and bring the second digit in the
  dividend down.

1
3) 497
3
Brother
1
9
30
Step Five Repeat or Remainder

• Repeat the steps in the same manner as before, as
  shown in the next set of slides.

1
3) 497
3
Rover
1
9
31
Repeat Step One - Divide

• Divide 3 into the new number.
• 3 will go into 19 six times.
• Write a 6 above the 9 because thats the current
  dividend.

1
6
3) 497
3
1
9
Dad
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Repeat Step Two - Multiply

• Multiply the divisor into the new number in your
  quotient.
• 3 x 6 18
• Write 18 below the number you just divided into.

1
6
3) 497
3
1
9
18
Mom
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Repeat Step Three - Subtract
1
6
3) 497
3
1
9
Sister
18
1
34
Repeat Step Four Bring Down
1
6

• If there are more digits in the dividend, repeat
  the procedure.
• Bring the third digit in the dividend down.

3) 497
3
1
9
18
1
7
Brother
35
Repeat Step Five Repeat or Remainder
1
6
5
r2

• If there are more digits in the dividend, repeat
  the procedure.
• If there are no more digits in the dividend,
  write the final subtraction answer as a
  remainder.
• If there is no remainder, youre finished! Pat
  yourself on the back for a job well done.

3) 497
3
1
9
18
1
7
15
Rover
2
36
Remember
Divide Multiply Subtract Bring Down Repeat or
Remainder
37
Lets do more problems together.
4)2960
6)3721
DMSBR
4)2961
9)2388
Complete these problems on a sheet of paper.
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The answers

• 2960 4 740
• 2961 4 74 r 1
• or
• 74.25

• 3721 6620 r 1
• Or
• 620.167
• 2388 9265 r 3
• Or
• 265.33

39

• You have just learned a mnemonic device for
  helping you to remember the steps in long
  division.
• You can use mnemonic devices anytime you need to
  learn material in any subject.

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Assignment

• Complete pages 215-216 problems 1-30.
• Write your name, date and assignment on the top
  of the page.