- (5 min) Mental Math
- What is 25% of 16? [4]
- What is 1/3 of 18? [6]
- What is the decimal equivalent of 1/3? [.333...]
- What is 2/3 + 2/3? Express your answer as a mixed number [1 1/3]
- What is 1/2 of 1/4? [1/8]
- What is 50% of 1/2? [1/4 or .25]

- (5 min) Review of selected problems from lesson 4 (no more than 3
problems)

- (5 min) Review of fractions:

- Mixed number conversion to improper fractions: Examples:

1 1/2 = 3/2 2 1/3 = 7/3 3 1/4 = 13/4 Ask: How many halves How many thirds How many fourths are in 1 1/2? are in 2 1/3? are in 3 1/4? [3] [7] [13]

- Common denominators: Examples:

- 2/3 + 2/5:

Find a number that both denominators divide into: 3 x 5 = 15

Multiply 2/3 top*and*bottom by 5 = 10/15

[Reason: to make the new denominator 15]

Multiply 2/5 top*and*bottom by 3 = 6/15

Add: 10/15 + 6/15 = 16/15 or 1 1/15. - 1/4 + 5/6

Ask the class:

What denominator should we use?

What do we multiply 1/4 by?

what do we multiply 5/6 by?

- 2/3 + 2/5:

- Mixed number conversion to improper fractions: Examples:
- (10 min) Discuss perimeter [length around the edge of a figure].
- Use this example:
- Discuss perimeter of various shapes:
- Perimeter of a square with sides 5 cm [P=20 cm]
- Perimeter of an equilateral triangle with sides 5 cm [P= 15 cm]
- Perimeter of an isoceles triangle with sides 3,3,4 cm [P= 10 cm]
- Circumference of circle with diameter 5 cm [= pi X diameter = 15.7 cm]
- Perimeter of regular hexagon with sides 5 cm [P= 30 cm]

(hex = six) - Perimeter of regular octagon with sides 5 cm [P= 40 cm]

(oct = 8 [think: octopus]) - Perimeter of regular pentagon with sides 5 cm [P= 25 cm]

(penta = 5 [think Chrysler symbol])

- (Remainder of class) In-class exercise

- Hand out homework as students successfully complete the in-class exercise.