2 Rational Numbers Operations 271t70

Rational Numbers Operations

Adding Rational Numbers Rule: O Same signs, add and keep. Different signs

subtract. Use the sign of the bigger number, then you’ll be exact! O Decimals: Line them up! O Fractions: Find a common denominator! O Mixed numbers: Change to improper Fractions!

Subtracting Rational Numbers Rule. O L.C.O. (Leave. Change. Opposite.) Leave the

first number alone, change subtraction to addition, and find the opposite of the 2nd number. O Then follow the adding rules!

Multiplying Rational Numbers Rule: O Decimals: Multiply like normal. Count the

number of decimal places in the problem to the right, and move that many places to the left in your answer. O Fractions: Multiply straight across and reduce if possible. O Mixed numbers: Change to improper fractions first, then follow fraction rule.

Dividing Rational Numbers Rule: O Decimals: Make the outside number a whole

number. What you do outside of the box you must do inside the box. Move your new decimal straight up and divide like normal. O Fractions: K.C.F. (Keep. Change. Flip.) Keep the first number. Change division to Multiplication. Flip the 2nd fraction. Then multiply straight across. Reduce if possible O Mixed Numbers: Make improper first, then follow fraction rule.

ACTIVITY O Students will be placed in assigned group. O Each person will have an answer sheet. O Work out the problem together, and record

your answer.

Question 1 O Write the rational number as a decimal: 5/8

O Answer: 0.625

Question 2 O Write the rational number as a decimal:

-1 2/3

O Answer: - 1.66…

Question 3 O Write the decimal as a fraction or mixed

number in simplest form: -0.35

O Answer: -7/20

Question 4 O Write the decimal as a fraction or mixed

number in simplest form: 24.2

O Answer: 24 1/5

Question 5 O Add:

7/10 + (-3/5)

O Answer: 1/10

Question 6 O Add: -2.4 + (-1.2)

O Answer: -3.6

Question 7 O Subtract: -3/4 -- 1/6

O Answer: -11/12

Question 8 O Subtract: 3.4 – 7.21

O Answer: -3.81

Question 9 O Multiply: (-3/5)(4/7)

O Answer: -12/35

Question 10 O Multiply: -1.3 * 4.25

O Answer: -5.525

Question 11 O Divide: -4/11 divided by 2/3

O Answer: -6/11

Question 12 O Divide: 6.4 divided by (-0.8)

Answer:

-8