decimal place value: decimal points are read as the word “and” place values to the right of the...

Decimal Place Value:•Decimal points are read as the word “and”•Place values to the right of the decimal point represent part of a whole•Read the numbers in groups of three then read the place value name•Place values to the right of the decimal point end with “ths”•Place values to the right of the decimal point “mirror” place values to the left of the decimal point

Decimal Place Value:

___ ___ ___ ___ ___ ___ ___

Th

ou

san

ds

Hu

nd

red

s Ten

sU

nit

s

Ten

ths

Hu

nd

red

ths

Th

ou

san

dth

s

Rounding Decimals:

• If the circled number is 0-4, the underlined number stays the same and all the digits to the right of the circled number fall off

• If the circled number is 5-9, the underlined number goes up one and all the digits to the right of the circled number fall off

Steps for Rounding:Step 1: Identify the place value you are

rounding to and underline itStep 2: Circle the number to the right

Step 3: Determine whether to “round up” or to “round down”

Rounding Practice Problems:

Nearest Tenth

Nearest Hundredt

h

4 . 5 7 6 4 . 5 7 6

1 3 . 8 0 4 1 3 . 8 0 4

1 7 9.8 5 6

1 7 9.8 5 6

4.6 4.58

13.8 13.80

179.9

179.86

Comparing Decimals:Steps for Comparing Decimals ValuesStep 1: List the numbers vertically

“Stack” the decimal pointsAdd zeros as place holders as

neededStep 2: Compare the whole number part then

compare the decimal parts moving to the right (as you would if you were alphabetizing words)Step 3: Put in the correct order (from least to

greatest or greatest to least)

Comparing Decimals Practice:

Practice Problems: Arrange each group of numbers in order from least to greatest.

0.342 0.304 0.324 0.340

2.37 2.7 2.3 2.73

0.304 0.324 0.340 0.342

2.3 2.37 2.7 2.73

To Compare = Be Fair!

Comparing Decimals Practice:

Practice Problems: Arrange each group of numbers in order from least to greatest.

5.23 5.023 5.203 5.032

1.010 1.101 1.011 1.110

5.023 5.032 5.203 5.23

1.010 1.011 1.101 1.110

To Compare = Be Fair!

Basic Operations with Decimals:

Addition and Subtraction

Step 1: Write the numbers vertically

“Stack” the decimal points

Add zeros as place holders

Step 2: Move the decimal point straight down into your answerStep 3: Add or subtract

Adding and Subtracting Decimals Practice:

Practice Problems: Find the sum for each.

2.3 + 3.71 + 27 = 33.01

2.30

+ 27.00 3.71

.01

1 1

33

Be Fair!


Practice Problems: Find the sum for each.

3.14 + 2.073 + 8.9 = 14.113

3.140

+ 8.9002.073

13

1 1

14

.1

Be Fair!


Practice Problems: Find the difference for each.

31.73 – 12.07 =

9 – 8.185 =

23.5 – 17.097 =

19.66

0.815

6.403

Be Fair!


Practice Problems: Find the sum or difference for each.

4.66 – 2.45 =

3 + 5.76 + 0.11 =

25 – 0.14 + 2.36 =

2.21

8.87

27.22

Be Fair!

Multiplying Decimals:Steps for MultiplicationStep 1: Write the problem vertically (just as you would a regular multiplication problem)Step 2: Ignore the decimal point(s) and

multiply as if you were multiplying whole numbersStep 3: Determine where the decimal point goes in the product

However many digits are to the right of the decimal point(s) in the problem… that’s how many digits are to be to the right of the decimal point in the product.

Multiplying Decimals Practice:

Practice Problems: Find the product of each.

2 x 3.14 = 6.28 Note (2 dp)

314x2

628



8.097 x .05 =0.40485 Note (5 dp)

8097 x5

40485



1.042 x 2.3 = 2.3966 Note(4 dp)

1042x23

312620840

23966

Equivalent methods are

possible

EXTENSION



4.7 x 1000 =

3 x 0.567 =

0.27 x 15 =

4 700

1.701

4.05

EXTENSION



(2.5)(1.5) =

(1.3)(7) =

5.41 x 200 =

3.75

9.1

1 082

EXTENSION

Dividing with Decimals:

There are 2 types of division problems involving decimal points:

No decimal in the divisor

Decimal in the divisor

Division with Decimals:NO decimal point in the divisor…

Step 1: Write the problem in the traditional long division formatStep 2: Move the decimal point in the dividend straight up into the quotientStep 3: Divide as usual

Remember to divide out one more place than you are rounding to…

Division with Decimals:Yes…Decimal point in the divisor…Step 1: Write the problem in the traditional long division formatStep 2: Move the decimal point in the divisor to the far right of the divisorStep 3: Move the decimal point the SAME

number of places in the dividendStep 4: Move the decimal point in the dividend straight up into the quotientStep 5: Divide as usual

Remember to divide out one more place than you are rounding to…

Division Practice:Practice Problems: Find the quotient for each.

3.753 3 =

8.7 100 =

245.9 ÷ 1000 =

0.65 ÷ 5 =

1.251

0.087

0.2459

0.13

3 3.753

1.251


428.6 ÷ 2 =

2.436 ÷ 0.12 =

4.563 ÷ 0.003 =

21.35 ÷ 0.7 =

214.3

20.3

1 521

30.5

EXTENSION

12

243.6

3 4563

7 213.5

2 428.6


97.31 ÷ 5 =

0.8542 ÷ 0.2 =

67.337 ÷ 0.02 =

1500.4 ÷ 1000 =

19.462

4.271

3 369.5

1.5004

EXTENSION

Problem Solving with Decimals:

Follow the correct Order of Operations only remember to apply the rules that go with decimals.

B.O.D.M.A.S.B – Brackets

O – OfD- DivisionM – Multiplication

A – AdditionS – Subtraction

Do whichever one comes first

working from left to right

Order of Operations Practice:

Practice Problems: Solve each by following the correct order of operations.

2.3 x 4 2 + 4 =

3.5 7 + 2.15 x 0.13 =

2(7 – 2.49) + 0.3 =

14 0.2 + (3.1 – 2.56) x 2 =

8.6

0.7795

9.32

71.08

EXTENSION

Order of Operations Practice:

Practice Problems: Solve each by following the correct order of operations.

5 + (7.8 – 5.5)2 – 9.3 =

(40 ÷ 0.5 x 7) + 5 – 14 =

-8 x 0.75 + 15.23 – 4 =

0.99

551

5.23

EXTENSION

GOOD LUCK

in

YOUR TEST

FINALLY

decimal place value: decimal points are read as the word “and” place values to the right of the...

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