Unit 3 Operations with Whole Numbers, Fractions, and Decimals
Lesson 3-1 and 3-2
Dividend- The number that is divided in a division problem
Divisor- The number that divides in a division problem
Quotient- The answer to a division problem
Steps
1.
2.
3.
4.
5.
to division:
41 r3
9)372
Divide in
36
Multiply
12
Subtract
9
Bring down
3
Repeat (if needed)
1.
Ex. 56÷8=7
7
8) 56
56 is the dividend
8 is the divisor
7 is the quotient
Will nine divide into 3? No. Look at the first two numbers, will nine divide into 37? Yes. How
many times? 4
2.
Multiply 4 and 9 and place the answer under the digits you just divided into (36)
3.
Subtract 36 from 37 = 1
4.
Bring down the two
5.
Repeat all steps if you brought a number down
1.
Does 9 divide into 12? Yes. How many times? 1
2.
Multiply the 1 and 9 and place the answer under the digits you just divided into (12)
3.
Subtract 9 from 12 = 3
Lesson 3-3
4. There is nothing to bring down, so the leftover number is your remainder
Multiplying Decimals Steps:
Problem-0.45 x 0.2
1. Ignore decimal points and multiply like normal
0.45
x 0.2
2. Count how many numbers are to the right of the decimal in each factor
0.090
0.45 x 0.2
2 numbers
1 number
3. Place decimal point in the answer so there are the same amount of numbers to the right of the decimal
point. In this answer, there are three numbers behind the decimal point.
Lesson 3-4
____
____
Steps for dividing with Decimals
0.15)9.9
15)9.9
____
____
1. Move decimal until the divisor is a whole number
15)990.
2. Move decimal in the dividend the same number of times. Add 0’s if needed 15)9.9
3. Place decimal in the quotient straight up from the decimal in the dividend
____
.
4. Divide
66.0
15)990. 15)990
15)990.0
-90
90
- 90
Lesson 3-5
00
Is it Multiplication or Division?
Multiplication: Situation requires larger number; the answer is greater than the given number
Division: Situation requires answer to show equal grouping
Ex.1 In 1976, gas cost about $0.36 per gallon.
If a gas tank held 22 gallons, how much did it
cost to fill the tank? Solve using multiplication.
22
X0.36
132
+ 660
$7.92
Ex. 2 A large bag of peanuts cost $12.00. If it
was divided into 40 equal size bags, how much
would each bag cast?
$0.30
40)12.00
12.00