1. 1-6 Real numbers and rational numbers
Objective: Compare and order rational numbers; evaluate expressions with rational numbers.
Mr. Pugh– algebra 1 A

2. Warm up
Evaluate 4n3 ÷m for m=-4, n=3

3. Put examples in the venn diagram

4. (Expressed in decimal form it is
definitions
A rational number is any number you can write in the form of a ratio (or fraction).
An irrational number cannot be written as a ratio of two numbers, like or .
(Expressed in decimal form it is
a decimal that goes on forever
with no pattern).

5. definitions
Integers are rational numbers because you can write them as ratios using 1 as the denominator. Rational and irrational numbers make up the set of real numbers All numbers on a number line

6. Examples (Think & Discuss)
Write 3 numbers that are rational numbers but not integers.
Show that 0.75 is a rational number by writing it as a ratio.
Where have you used irrational numbers?

7. When you compare two real numbers, only one of these can be true:
comparing
When you compare two real numbers, only one of these can be true:
a < b or a = b or a > b
less than equal to greater than

8. Rewrite the answer using the symbol for less than
Example
Use a number line to compare − 1 8 and − 1 2
Rewrite the answer using the symbol for less than

9. example
Evaluate a + 2b where a = and b = − 5 8

10. example Use the expression 5/9(F - 32) = C to change from the
Fahrenheit scale to the Celsius scale.
What is 10 degrees in Celsius?

11. definition
The reciprocal, or multiplicative inverse, of a rational number 𝑎 𝑏 is 𝑏 𝑎 .
Zero does not have a reciprocal because division by zero is undefined.
Ex: What is the reciprocal of 2 3 ? What is the reciprocal of 3?

12. Complete the chart
Number
Reciprocal
Product 3
= _____ 5
- ½
What is the product of a number and its reciprocal?

13. 𝑥 𝑦 =𝑥 ÷𝑦
example
Evaluate 𝑥 𝑦 for x = − 3 4 and y = − 5 2

14. Pg 32–33 #1-19 odd, 25, 27, 36 No work? No credit!
homework
Pg 32–33 #1-19 odd, 25, 27, 36 No work? No credit!