Rational Numbers and Decimals

5.5

Natural Numbers

• Counting Numbers• 1,2,3,4,5,6,7…

Whole Numbers

• 0+ Natural Numbers• 0,1,2,3,4,5,6…

Integers

• Negative Numbers + Whole Numbers• …-3, -2,-1, 0, 1, 2, 3…

Rational Numbers

• Integers + every number that can be written as a fraction

• -2, -3/2, -1, -0.4,0,1,1.25, 2….

Identify sets to which numbers belong

• -5Integers, rational number• 2/7Rational number• 4Natural , whole , integer, rational number

• 0Whole, integer, rational number• 8.5Rational number

Fraction to Decimal

• Divide the denominator into numerator• Two types:– Terminating : ends– Repeating: never ends but keeps repeating

Turn into a decimal5

8

Turn into a decimal3

11

Decimal to Fraction

• 1 decimal place = put over 10• 2 decimal places = put over 100• 3 decimal places = put over 1,000• 4 decimal places = put over 10,000 and so on…

Then reduce!!!

Turn to a fraction 0.6

Turn to a fraction 0.45

To write a repeating decimal as a fraction

1. Set n= decimal2. Multiply both sides of the equation by either

(10,100,1,000, 10,000, …) depending on how many numbers repeat

3. Subtract step 2 from step 14. Solve for n

Turn into a fraction

0.56

Turn into a Fraction

0.7

Turn into a Fraction

0.12

Homework

• Page 242 (26-31 all, 36-50 even, 59-62 all)