DMSB What is DMSB? You wonder? This stands for the order of long division Divide Multiply Subtract Bring Down
Take a look at this division problem: This is the divisor. The divisor is the number of groups we are dividing into or the number we are dividing by.
3 )74
This is the dividend. The dividend is the number we break into groups.
Looks scary, huh? Well, when you use DMSB It can be simple. Move to the next slide to get started!
DIVIDE First, we want to DIVIDE. Ask yourself: “How many times can 3 go into 7?” 3 )74
Think of your multiplication facts:
Or, draw an array:
3x1=3 3x2=6 3x3=9
OOO OOO OOO
DIVIDE You want to find the closest number to 7 without going over!
Think of your multiplicatio In this case it’s 2 times n facts: because 3 x 2 is 6 3x1=3 3 times is too high since 3 x 2 = 6 3x3=9 3x3=9
Or, draw an array: OOO OOO OOO
DIVIDE Now, place your 2 above the 7, because 3 goes into 7 two times. 2 3 )74
The 2 becomes the first part of your quotient. The quotient is the answer in division.
You’ve just completed the divide. Now, we’ll move onto multiply.
MULTIPLY Next, you want to multiply 3 times 2:
3 x 2= 6
2 3 )74 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!
MULTIPLY That was a really simple step! Now, we want to move on to subtract!
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!
BRING DOWN When you bring down, you’re moving the second part of your dividend into your workspace: 2 3 )74 -6 14
BRING DOWN Wow! You’ve just completed every step of DMSB! But, wait! There’s more! 2 3 )74 -6 14 We now have a new number and we have to start all over again…
DIVIDE First, we want to DIVIDE. Ask yourself: “How many times can 3 go into 14?” 2 3 )74 -6 14
Think of your multiplication facts: 3x1=3 3x2=6 3x3=9 3 x 4 = 12 3 x 5 = 15
Or, draw an array: OOO OOO OOO OOO OOO
DIVIDE 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
Think of your Or, draw an multiplication array: facts:
3x 3x 3x 3x 3x
1=3 2=6 3=9 4 = 12 5 = 15
OOO OOO OOO OOO
DIVIDE Now, place your 4 above the 4, because 3 goes into 14 four times. 24 3 )74 -6
14
The 4 becomes the second part of your quotient. You’re almost done!
You’ve just completed the divide. Now, we’ll move onto multiply.
MULTIPLY Next, you want to multiply 3 times 4: 24 3 )74 -6 14 3 x 4 = 12 12 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!
MULTIPLY That was a really simple step! Now, we want to move on to subtract!
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 -6 14 -12 2 Good! We know 14-12 = 2. Leave your 2 in it’s spot, because we’re going to use it for the bring down!
BRING DOWN When you bring down, you’re moving the next part of your dividend into your workspace: 24 3 )74 ? -6 14 -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.
REMAINDER The remainder is what you have left over (or what is remaining) after you have nothing to bring down: 24 3 )74 -6 14 -12 2
R-2
In this problem, the remainder is 2 because 14-12 = 2. Write your remainder next to your answer.
Here is what your division problem should look like: 24 R - 2 3 )74 -6 14 -12 2
• 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)81 81 is the dividend • The quotient is the answer in division. • Remember! You want to keep going until you have nothing to bring down.
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
Check Yourself! 12 r 2 5)62 -5 12 -10 2
39 r 0 2)78 -6 18 -18 0
13 r 1 7)92 -7 22 -21 1
11 r 1 4)45 -4 05 -4 1
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