Transcript 1-2

1-2 Divide Multi-Digit Whole Numbers
Learn use the algorithm for division and
interpret the quotient and remainder in a
real-world setting.
1-2 Divide Multi-Digit Whole Numbers
Vocabulary
dividend
divisor
1-2 Divide Multi-Digit Whole Numbers
Every year students take the school bus to and
from school. There are about 4,80,000 school
buses in the United States, and there are
25,920,000 total students who take the bus.
You can use division to find out how many students
are on each bus.
To divide multi-digit numbers you can use long
division. The number to be divided is the
dividend. The divisor is the number by which the
dividend is divided.
____________________
480,000)25,920,000
Divisor
Dividend
1-2 Divide Multi-Digit Whole Numbers
Additional Example 1: Finding Group Size Using
Division.
There are 435 members of the United States
House of Representatives. It the member
where split into 15 equal-sized committees,
how many representatives would be in each
committee?
Step 1: Decide where to place the first digit in the
quotient.
x
15) 435
no You cannot divide 4 by 15.
x
15) 435
yes You can divide 43 by 15.
So, place the first digit of the quotient in the tens place.
1-2 Divide Multi-Digit Whole Numbers
Continued: Example 1
Step 2: Divide the tens. 15 ) 43
2
15) 435
- 40
3
Multiply. 15 x 2
Subtract. 43 – 40
Compare.3 < 15
1-2 Divide Multi-Digit Whole Numbers
Continued: Example 1
Step 3: Divide the ones. 15 ) 435
29
15) 435
- 30
135
- 135
Multiply. 15 x 9
Subtract 135-135
0
So, each committee will have 29 representatives.
1-2 Divide Multi-Digit Whole Numbers
Check It Out: Example 1
A tour operator is organizing 442 people on
buses for a day trip. If they wish to separate
the people equally on 13 buses, how many
people are on each bus?
Step 1: Decide where to place the first digit in the
quotient.
x
13) 442
no You cannot divide 4 by 13.
x
13) 442
yes
You can divide 44 by 13.
So, place the first digit of the quotient in the tens place.
1-2 Divide Multi-Digit Whole Numbers
Continued: Check It Out Example 1
Step 2: Divide the tens. 13 ) 44
4
Multiply. 13 x 4
13) 442
Subtract. 44 – 42
- 42
Compare.2 < 13
2
Step 3: Divide the ones. 13 ) 442
34
Multiply. 13 x 4
13) 442
- 39
52
Subtract 52-52
-52
0
So, each bus will have 34 people.
1-2 Divide Multi-Digit Whole Numbers
Remember!
To estimate a quotient, use compatible
numbers.

1-2 Divide Multi-Digit Whole Numbers
Additional Example 2: Finding Numbers of
Groups Using Division
A store manager has 224 pairs of jeans to
stock on the store’s shelves. If each shelf can
hold 18 pairs of jeans, how many shelves does
the manager need to stock all the pairs
of jeans?
Step 1: Use an estimate to place the first digit in the
quotient.
Divide:
Estimate:
224 ÷ 18 = n
200 ÷ 20 = 10
18) 224
So, n ≈ 10.
So, the first digit of the quotient will be in the tens place.
1-2 Divide Multi-Digit Whole Numbers
Continued: Example 2
Step 2: Divide the tens. 18 ) 22
1
Multiply. 18 x 1
18) 224
Subtract. 22 – 18
- 18
4
Step 3: Divide the ones. 18 ) 44
1
18) 224
Multiply. 18 x 1
- 18
44
Subtract. 44 – 36
- 36
Compare 8 < 18
8
1-2 Divide Multi-Digit Whole Numbers
Continued: Example 2
Twelve shelves will not be enough hold all the
jeans. Another shelf will be needed to hold the
remaining 8 jeans. The quotient must be
rounded up to the next whole number.
Since 12 is close to the estimate of 10, the
answer is reasonable. So, the manager will need
13 shelves.
1-2 Divide Multi-Digit Whole Numbers
Check It Out: Example 2
A store manager has 338 pairs of jeans
to stock on the store’s shelves. If each
shelf can hold 24 pairs of jeans, how
many shelves does the manager need to
stock all the pairs of jeans?
Step 1: Use an estimate to place the first digit in the
quotient.
Divide:
Estimate:
338 ÷ 24 = n
24) 338
340 ÷ 20 = 17 So, n ≈ 17.
So, the first digit of the quotient will be in the tens place.
1-2 Divide Multi-Digit Whole Numbers
Continued: Check It Out Example 2
Step 2: Divide the tens. 24 ) 33
1
Multiply. 24 x 1
24) 33
- 24
Subtract. 33 – 24
9
Step 3: Divide the ones. 24 ) 98
14
24) 338
Multiply. 24 x 4
- 24
Subtract 98-96
98
- 96
Compare 2 < 24
2
1-2 Divide Multi-Digit Whole Numbers
Continued: Check It Out Example 2
Fourteen shelves will not be enough hold all the
jeans. Another shelf will be needed to hold the
remaining 2 jeans. The quotient must be
rounded up to the next whole number.
Since 14 is close to the estimate of 17, the
answer is reasonable. So, the manager will need
15 shelves.