The document outlines a math lesson plan that includes reviewing fractions and greatest common factors, working with decimals through addition, subtraction, multiplication, division, and converting between fractions and decimals, and using Khan Academy for additional practice on specific topics from November 10th and 17th. Students will work through decimal word problems, comparisons, and operations during class work.

1. November 14, 2012
Today:
Warm-Up: Review Fractions & GCF
Decimals: +, -, x, ÷
STAR Math
Khan Academy: Nov. 10th & 17 Topics

2. Warm-Up:
Khan Academy Help: Dividing Fractions Word Probs.

3. Warm-Up:
3. Which Fraction is larger: 4/6 or 7/10?
4. 2/5 + 7/8 = 5. 3 3/7 + 2 3/8 =
6. 6/11 - 5/12 = 7. 3 2/7 - 2 1/8 =
8. 8/15 • 3/11 = 9. 3 2/7 • 2 1/8 =
10. 8/15 ÷ 3/11 11. 3 2/7 ÷ 2 1/8 =
=
12. Find the Prime Factorization of 60
13. Simplify, using GCF: 144/150

4. Decimals: Objectives
1. Read decimals 6. Add decimals
2. Write decimals 7. Subtract decimals
3. Compare the size of 8. Multiply decimals
decimals to one 9. Divide decimals
another 10. Round decimals to
4. Convert fractions to nearest tenth
decimals 11. Round decimals to
5. Convert decimals to nearest hundredth
fractions

5. Decimals: Definition
 A decimal is a fraction with a denominator that is a
multiple of 10. The decimal (.) is used to indicate place
value. Examples:
3
equals 0.3 stated as "three tenths"
10
18
equals 0.18 stated as "eighteen hundre dths"
100
Caution: each decimal expression with a value
less than 1 is preceded by a leading zero to
emphasize the presence of a decimal. For
example, .7 is correctly written as 0.7

6. Decimals: Place values

7. Decimals: Reading
 Reading
1. Read the whole number on the left
2. Read the decimal point as the word
“and”
3. Read the decimal fraction on the right
Example: 8.3 = “eight and three tenths”
4.06 = “four and six hundredths”
0.5 = “five tenths

8. Decimals: Writing
 Write as follows
1. The whole number (if none, then write a zero - (“0”)
2. The decimal point to indicate the place of value
3. The decimal fraction portion of the number
Examples: “Seven and five tenths” = 7.5
“One hundred twenty-five thousandths” = 0.125

9. Decimals: Comparing Values
 Zeros do not change the value of the number
whether added at the beginning or the end,
but they are unsafe as trailers.
 Ex: .7 is the same numerical value as 0.7
12.6250 is the same value as 12.625
but, 30.0 can be misinterpreted as 300!
Use leading zeros; AVOID trailing zeros

10. Decimals: Comparing Values (cont’d)
 Zeros added within a decimal number
change the value dramatically
 Example: 0.375 is NOT the same as 0.0375
2.025 is NOT the same as 20.025

11. Decimals: Comparing Values (cont’d)
 Different whole numbers
 Ifwhole numbers are present and different,
whole numbers are compared to determine
largest
 Example: 4.8 is greater than 2.9
 Same or no whole number
 The number in the tenths place determines
largest
 Example: 0.45 is larger than 0.37

12. Decimals: Comparing Values (cont’d)
 Same or no whole number, and the number
in the tenths place is the same
 The decimal with the highest number in the
hundredths place is the largest
 Examples: 0.67 is larger than 0.66
0.17 is larger than 0.14
0.09 is larger than 0.08

13. Decimals: Adding and Subtracting
 Place the numbers in the columns so the decimals
are lined up. Add or subtract from left to right.
 Examples:
16.4 .7
21.8 .750 .7
+ 3.0 + .324 - .050
Safety Point: Zeros may be added to help line up
decimals – don’t include in final answer!

14. Decimals: Multiplying
 Place decimal correctly!
 Multiply numbers; in the product (answer), count
decimal places right to left equal to the total
decimal places in the numbers being multiplied.
 Example:
1.2
.7
x 3.2
x .050
24
36
384. = 3.84

15. Decimals: Multiplying (cont’d)
 Add zeros where needed to ensure correct
placement of decimal in answer
 Example: 0.11 x .33
0.11
.12
x 0.33
x .14
33
33
0363. = 0.0363

16. Multiplying by Decimal Movement
 Multiplying by 10, 100, 1,000 can be done by
moving decimal to the right one space for each
zero in the number by which multiplying
 Example: 1.6 x 10 = 1.6 = 16
5.2 x 100 = 5.20 = 520
.7 • 10 = .8 • 100 =

17. Decimals: Dividing
 Same as for whole numbers
Q uotient
Divisor Dividend
 Example: 9 27 = 27 divided by 9

18. Decimals: Dividing a Decimal
 To divide by a whole number, place decimal in
quotient directly above decimal in dividend
3 .5
5 1 7 .5
8 22.3
- 15
25 4 35.7
- 25
0

19. Decimals: Dividing by a Decimal
 Move the decimal in the divisor to the right
until the number is a whole number. Then move
the decimal in the dividend the same number of
spaces. 2 3 .2
. 3 6 9 .6
0.3 6.96 - 6
9
- 9
.8 12.1 6
-6
0

20. Class Work:
Decimal Handout:
Every Other Problem
Girls: Begin with First Problem
Gents: Begin with Second
Problem

22. Decimals: Changing from Fractions
 Rewrite fraction in division format
 Divide the numerator by the denominator and add
zeros as needed
 Method can be used to compare fraction size
0.4
2 1 1
5 2.0 0.333... and 0.166...
5 3 6
1 1
Therefore is larger than
3 6