DivisionDivisionby One Digitby One DigitDivisorsDivisorsAllegra James Allegra James and Larry Wershbaleand Larry Wershbale

Media Design and ProductionMedia Design and Production

ISTC 665ISTC 665

Adapted by Mr. HillAdapted by Mr. Hill

• Dividing these 16 cards into 4 equal groups, gives you 4 groups that have 4 cards in each of the groups:

What are you doing when What are you doing when you divide?you divide?

• When you divide, you are trying to split something into equally numbered groups

• Take these 16 cards:

Division by One-digit DivisorsDivision by One-digit Divisors

• Today you will learn how to divide a three-digit dividend by a one-digit divisor, to get a quotient without a remainder

• Let’s review these terms

What are the parts of a What are the parts of a division problem?division problem?

• The dividend is the number you are dividing• The divisor is the number you are dividing by• The quotient is the evenly divided result• The remainder is what is left over that cannot

be evenly divided

When we write the problem When we write the problem like this:like this:

136 ÷ 5 = 27 r 1136 ÷ 5 = 27 r 1

136 is the

dividend

5 is the

divisor

27 is the

quotient

1 is the

remainder

When writing it like this:When writing it like this:

136, the dividend,

moves here

5, the divisor, moves

to here

27, the quotient,

stays here

1 is the remainder1365

27 r 1

How do you solve a How do you solve a division problem?division problem?

• Solving a division problem is a step by step process

• The method we will learn today is based the words for the people in our families.

• They are:

Father Mother Sister Brother Rover

The “Family” MethodThe “Family” Method

Father = Find

Mother = Multiply

Sister = Subtract

Brother = Bring Down

Rover = Remainder / repeat

FatherFather• Father stands for find

• Start by looking at the first number in the dividend

• Find the multiple of the divisor that comes closest to that number, without going higher

• Use your knowledge of math facts, or a multiplication grid

7113

FFather = ather = findfind the number closet to the first digit the number closet to the first digit

• In the 3’s, the number closest to 7, but not more than 7, is 6

• The other factor is 2

6

• Put a 2 above the 7

2

2

MMother = other = multiplymultiply the number that is the the number that is the factor that you found times the divisorfactor that you found times the divisor

• You found 2, multiply it times the divisor, 3

• 2 times 3 equals 6

2 X 3 = 6

• Put a 6 under the 7

7113

2

6

SSister = ister = subtractsubtract the number you got by the number you got by multiplying the divisor, multiplying the divisor,

from the number in the dividendfrom the number in the dividend

• You got a 6 when you multiplied

• Subtract 6 from 7 7113

2

6• 7 – 6 = 1

–

1

• The difference must be smaller than the divisor!!!The difference must be smaller than the divisor!!!

BBrother = rother = bring downbring down the next number, the next number, from the number in the dividendfrom the number in the dividend

• Bring down the next number in the dividend

• The new number you have is 11

• Now start over again with Father for the ten’s

7113

2

6–

11

1

RRoverover == repeat repeat the processthe process

• Father: 9 is the closest multiple, the other factor you found is 3

• Mother: 3 X 3 = 9, put a 9 under the 11

• Sister: subtract 9 from 11 11- 9 = 2

7113

2

6–

11

1

• Brother: bring down the 1

3

9–21

RRoverover == repeat repeat the processthe process

• Father: 21 is the closest multiple, the other factor is 7

• Mother: 7 X 3 = 21, put 21 under the 21

• Sister: subtract 21 from 21 21- 21 = 0

• Brother: nothing’s left, you’re done!

7113

2

6–

11

1

3

9–2121–

0

7

8644

2

8–

6

6

Now, let’s practice!Now, let’s practice!

• Father

• Mother

• Sister

• Brother

• Rover

0

2

4 8

Now, let’s do the second stepNow, let’s do the second step

• Father

• Mother

• Sister

8644

2

8–

06

6

• Brother

• Rover

1

4–24

4

Now, let’s do the last stepNow, let’s do the last step

• Father

• Mother

• Sister

• Brother

• Rover

8644

2

8–

06

6

1

4–2424–

0

6