1. Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.

2. Chapter 3 Decimals Prepared by Dr. Elena Skliarenko
Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.

3. Learning Unit Objectives#3
Fractions
Learning Unit Objectives
LU3.1
Rounding Decimals; Fractions & Decimal Conversions
Explain the place values of whole numbers and decimals; round decimals
Convert decimal fractions to decimals, proper fractions to decimals, mixed numbers to decimals, and pure and mixed decimals to decimal fractions
Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.

4. Learning Unit Objectives#3
Fractions
Learning Unit Objectives
LU3.2
Adding, Subtracting, Dividing, and Multiplying Decimals
Add, subtract, multiply, and divide decimals
Multiply and divide decimals by shortcut methods
Complete decimal applications in foreign currency
Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.

5. Learning Unit Objectives#3
Fractions
Learning Unit Objectives
LU3.3
Using a Calculator to perform operations with Decimals
Converting fractions to decimals and decimals to fractions
Adding, subtracting, multiplying, and dividing decimals
Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.

6. Decimal place-value chart
Figure 3.1
Thousands
Tens
Ones
Hundredths
Tenths
Ten Thousandths
Thousandths
Hundred Thousandths
1,000
100 10 1
1 .
1 .
10,000
100,000
Decimal Point
and
Hundreds
Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.

7. Rounding Decimals .33 .3272727 .337272 Step 1. Identify the place
value of the digit you want
to round
Step 3. Drop all digits to the right of the identified digit
Step 2. Identify the digit to the right.
If 5 or more, increase the identified digit
by 1. If less than 5 do not change
.33
Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.

8. Converting Proper Fractions to Decimals
.75
2.8 20
EQUALS 3 4
.75
Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.

9. Converting Pure Decimals to Decimal Fractions24
Step 1 24 1
Step 2
.24
Places 2
Step 3 24
100
Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.

10. Converting Mixed Decimals to Decimal Fractions
Step 1
545
545 1
Step 2
.54 1 2
Places 3
Step 3
545
1000
Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.

11. Adding and Subtracting Decimals
7.0000
5.3000
.0003
5.0200
Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.

12. Multiplying Decimals 9.09 x 3.8 3 decimal places 34542 34.542 17275
.17275
5 decimal places
6.91 x
Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.

13. Dividing Decimals 3 Steps 4.5 82.89 45. 828.9 18.42 45. 828.90 45 378
Question
3 Steps
Make the divisor a whole number by moving the decimal point to the right
Move the decimal point in the dividend to the right the same number of places as in step 1. If there are not enough places, add zeros to the right of the dividend.
Place the decimal point in the quotient above the new decimal point in the dividend. Divide as usual.
Answer
18.42 45
378
360
189
180 90
Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.

14. Key Currency Cross Rates
Decimals Applications in Foreign Currency
Key Currency Cross Rates
Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.

15. Shortcuts for Multiples of 10
Count the zeros in the multiplier
Move the decimal point the same
number of spaces to the right
Multiplication
6890
68.9
6.89 x 1000
6.89 x 10
6.89 x 100
689
Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.

16. Shortcuts for Multiples of 10
Division
Count the zeros in the divisor
Move the decimal point the same
number of spaces to the right
.00689
6.89 / 1000
6.89 / 10
.689
6.89 / 100
.0689
Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.

17. Proper use of the calculator
Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.

18. Converting mixed numbers to decimals and decimals to mixed numbers a b/c
For example , to convert 1 ¾ into decimal you have to follow these steps.
Step 1. Enter 1 ¾ in your calculator
1 a b/c 3 a b/c 4  1 r 3 r 4
Step 2. Press equal sign button =
Step 3. Press the “magic” button a b/c  1.75
To convert decimal number into mixed number or fraction undertake the following steps:
Step 1. Enter decimal number in your calculator
Step 2. Press equal sign button
Step 3. Press the “magic” button a b/c
Copyright © 2005 McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved.