add and subtract rational numbers.

1
ObjectiveThe student will be able to

• add and subtract rational numbers.
• compare and order rational numbers.
• SOL none

Designed by Skip Tyler, Varina High School
2
Find the sum.1) -2.304
(-0.26)

• Line up the decimals and add (same signs).
• -2.564

Get a common denominator and subtract.
3
Find the difference.
3)
Change subtraction to adding the opposite.
Get a common denominator.
Subtract and keep sign of the larger number.
4
Find the difference.
Change subtraction to adding the opposite.
Get a common denominator and subtract.
5
5) Solve 6.32 y if y -3.42
Substitute for y 6.32 - (-3.42) 6.32 3.42 9.74
6
Find the solution6.5 9.3 ?

1. -3.2
2. -2.8
3. 2.8
4. 3.2

7
Find the solution

1. .

8
A rational number is a number

• that can be written as a fraction.
• How can these be written as a fraction?
• 3

9
Inequality Symbols
10
Ordering Rational Numbers

• 2 ways to order from least to greatest
• Get a common denominator
• Change the fractions to decimals
  (numerator ? demoninator)

11
Which rational number is bigger?

• 1) Get a common denominator.

2) or convert the fraction to a decimal. 0.363
lt 0.375
12
Which rational number is bigger?

• Get a common denominator
• or convert to a decimal
• 1.75 lt 1.83

13
Which symbol makes this true?

1. lt
2. gt

14
Which symbol makes this true?
-2
-1
__
4
9

1. lt
2. gt