Unit Conversions

1. Unit Conversions • 1 foot = 12 inches • 4 feet = 4 x 12 inches = 48 inches • 1 centimeter = 10 millimeters • 10 centimeters = ? millimeters

2. Unit Conversions • 1 pound = 16 ounces • 5 pounds = ? ounces • 32 ounces = ? pounds

3. Introduction to Algebra

4. Terms Quiz • Product • Sum • Difference • Quotient • Subtraction • Multiplication • Division • Addition

5. Variable • A variable is a letter that represents an unknown number. • Example • 15 people are on the bus, x people are going to get off the bus at the next stop. • x is our variable, because we don’t know what it will be.

6. Expressions • We can use variables to help us solve word problems. • To solve a word problem we need to change the words into a math expressions.

7. Practice • 7 more than a number • 7 + n • 7 less than a number • n – 7 • A number separated into 6 groups • n ÷ 6

8. More Practice • The sum of a number and 10 • n + 10 • The product of a number and 4 • 4n (same as 4 x n) • The difference of 10 and a number • 10 - n

9. Story Problems • 15 people are on the bus, x people are going to get off the bus at the next stop. How many people will be left on the bus? • What expression would we use to solve this?

10. Operation • When people get off a bus what happens to the total number of people on the bus? • Will we need addition, subtraction, multiplication, or division? • Expression: 15 – x = total people on bus

11. Try This One! • Best Buy needs to purchase D number of DVD’s. Each DVD costs $15. Write an expression that shows how much Best Buy spends on DVD’s.

12. Answer • $15 x D = total money • We can use this expression for any number of DVD’s Best Buy buys.