Rational Numbers

Some Definitions

• Rational Number: Any number that can be converted into a fraction ( Examples: ¼, 3, 4.25, 0).

• Fraction: A part of a whole ( ¼ , ¾).• Mixed Number: A whole number and a fraction (1 ¼

)• Terminating Decimal: A decimal number that stops

(3.75, 4.3, 8.3245).• Repeating Decimal: A decimal number that has a

repeating pattern (3.757575… , 2.345345… )

Adding Decimal Numbers

• To add decimal numbers, line up the addends by the decimal place and add.

• Make sure the place values line up properly.

Complete #1-5

Applying Integer Rules

• We can apply the same rules for integers to rational decimal numbers.

• Rule 1: If the signs are the same, add and keep the sign the same.

• Rule 2: If the signs are different, subtract and keep the sign of the larger number.

Complete #6-10

Adding Fractions and Mixed Numbers

• When you add fractions, you must first find a common denominator.

• We find a common denominator by finding the least common multiple for the denominators of our addends.

• Make sure your answer is always in lowest terms.

Complete #11-15

Applying Integer Rules

• We can also apply our integer rules to fractions and mixed numbers.

• If we need to borrow, take one away from the whole number and add the appropriate amount to the numerator.

Complete #16-20

Subtracting Rational Numbers

Use your subtraction rules:

• Change subtraction to addition and find the opposite of the second number.

• Go back to addition rules.

Multiplying Rational Numbers

Multiplying Decimals

• Line up the numbers justified right. • Multiply the factors.• Count the decimal places in each factor and

add. • Move the decimal place that many times to

the left.

Multiplying Fractions

• Change mixed numbers to improper fractions.– Cross cancel and multiply OR– Multiply and reduce

Dividing Rational Numbers

Dividing Decimals

• Set it up. (First in)• Move the decimal on the outside.• Move the decimal on the inside the same

number of times.• Rewrite and divide.

Dividing Fractions

• Change mixed numbers to improper fractions.

•KFC