1. Lecture on LONG DIVISION

2. Long Division L.O - To know how to use DMSB to work out long division.
R.T-
(Remember To)
Divide
Multiply
Subtract
Bring Down

3. This stands for the order of long division
DMSB
What is DMSB? You wonder?
This stands for the order of long division
Divide
Multiply
Subtract
Bring Down

4. Long Division Take a look at this division problem: 3 )74
Looks scary, huh? Well, when you use DMSB It can be simple. Move to the next slide to get started!
This is the dividend. The dividend is the number we break into groups.
This is the divisor. The divisor is the number of groups we are dividing into or the number we are dividing by.

5. DIVIDE Or, draw an array: O O O 3 x 1 = 3 First, we want to DIVIDE.
Ask yourself: “How many times can 3 go into 7?”
3 )74
Think of your multiplication facts:
3 x 1 = 3
3 x 2 = 6
3 x 3 = 9
Or, draw an array:
O O O

6. DIVIDE Think of your multiplication facts: 3 x 1 = 3 3 x 2 = 6
You want to find the closest number to 7 without going over!
In this case it’s 2 times because 3 x 2 is 6
3 times is too high since 3 x 3 = 9
Think of your multiplication facts:
3 x 1 = 3
3 x 2 = 6
3 x 3 = 9
Or, draw an array:
O O O

7. DIVIDE Now, place your 2 above the 7, because 3 goes into 7 two times.
3 )74
You’ve just completed the divide. Now, we’ll move onto multiply.
The 2 becomes the first part of your quotient. The quotient is the answer in division.

8. MULTIPLY Next, you want to multiply 3 times 2: 2 3 )74 3 x 2= 6 6
We do this because we said that 3 can go into 7 two times, but now we have to find out how close to 7 we can get. So we multiply!

9. MULTIPLY That was a really simple step!
Now, we want to move on to subtract!

10. SUBTRACT
Now that we know how many times 3 goes into 7, we have to subtract to see the difference between the numbers: 2
3 )74 -6 1
Good! We know 7 – 6 = 1. Leave your 1 in it’s spot, because we’re going to use it for the bring down!

11. BRING DOWN
When you bring down, you’re moving the second part of your dividend into your workspace: 2
3 )74 -6 14

12. BRING DOWN
Wow! You’ve just completed every step of DMSB! But, wait! There’s more! 2
3 )74
We now have a new number and we have to start all over again…

13. DIVIDE Think of your multiplication facts: 3 x 1 = 3 3 x 2 = 6
Or, draw an array:
O O O
First, we want to DIVIDE.
Ask yourself: “How many times can 3 go into 14?” 2
3 )74

14. DIVIDE Or, draw an array: O O O 3 x 1 = 3 3 x 2 = 6 3 x 3 = 9
Think of your multiplication facts:
3 x 1 = 3
3 x 2 = 6
3 x 3 = 9
3 x 4 = 12
3 x 5 = 15
Or, draw an array:
O O O
You want to find the closest number to 14 without going over!
In this case it’s 4 times because 3 x 4 is 12
5 times is too high since 3 x 5 = 15

15. DIVIDE
Now, place your 4 above the 4, because 3 goes into 14 four times. 24
3 )74
You’ve just completed the divide. Now, we’ll move onto multiply.
The 4 becomes the second part of your quotient. You’re almost done!

16. MULTIPLY Next, you want to multiply 3 times 4: 24 3 )74 -6 14
3 x 4 =
We do this because we said that 3 can go into 14 four times, but now we have to find out how close to 14 we can get. So we multiply!

17. MULTIPLY That was a really simple step!
Now, we want to move on to subtract!

18. SUBTRACT
Now that we know how many times 3 goes into 14, we have to subtract to see the difference between the numbers: 24
3 )74
-12 2
Good! We know = 2. Leave your 2 in it’s spot, because we’re going to use it for the bring down!

19. BRING DOWN
When you bring down, you’re moving the next part of your dividend into your workspace: 24
3 )74 ?
-12
2 ?
But wait!! There’s nothing to bring down!! This is OK! You have no more numbers in your dividend to add to your workspace so you’re almost done! If there was a third number in our dividend, then we would start DMSB all over again! You want to keep going until you have nothing to bring down.

20. REMAINDER
The remainder is what you have left over (or what is remaining) after you have nothing to bring down:
R - 2
3 )74
-12 2
In this problem, the remainder is 2 because = 2. Write your remainder next to your answer.

21. Here is what your division problem should look like:
3 )74
-12 2

22. Let's Review!
DMSB is the order of operations for division. It stands for Divide, Multiply, Subtract, Bring Down
The divisor is the number of groups we are dividing into or the number we are dividing by. In 2)81 2 is the divisor.
The dividend is the number we break into groups. In 2) is the dividend
The quotient is the answer in division.
Remember! You want to keep going until you have nothing to bring down.

23. Do It Yourself!
Now, try these problems on your own! Remember DMSB. When you’re finished, move to the next slide to check your answers!
5)62
2)78
7)92
4)45

24. Check Yourself! 12 r 2 5)62 -5 12 -10 2 39 r 0 2)78 -6 18 -18 13 r 1
13 r 1
7)92 -7 22
-21 1
11 r 1
4)45 -4 05

25. You did a really awesome job with DMSB. Remember
You did a really awesome job with DMSB. Remember! Long division can be easy! And when you need a little help just think of DMSB:
Divide
Multiply
Subtract
Bring Down
Keep dividing!