Tips For Working With Fractions

Standard Students will demonstrate the ability to read and draw using the proper scale. a. Demonstrate the ability to measure using the architect’s scale.

Tip One: Adding To quickly add fractions, add the numerators together, and leave the denominators if they are the same number (if not find a common denominator) 3/8 + 5/8 is 8/8 = 1 1/4 + 1/2 is 1/4 + 2/4 = 3/4

When solving practice problems Write the equation on your notes page in the space provided Solve the equation Record your answer and circle it When prompted enter your answer into Nearpod

Calculate: 2–1/4 + 3–3/16 + 4–5/8

Answer: 2–1/4 + 3–3/16 + 4–5/8 = 10–1/16 Find a common denominator (16), then make 1/4 = 4/16, then make 5/8 = 10/16 and add those numbers to 3/16, then add the whole numbers together

Calculate: 2–7/16 + 1 + 3–17/32

Answer: 2–7/16 + 1 + 3–17/32 = 6–31/32 Find a common denominator (32), then make 7/16 = 14/32and add that to 17/32, then add the whole numbers together

Tip Two: Subtracting To subtract fractions, subtract the numerators, and leave the denominators if they are the same number (if not find a common denominator) 5/8 – 3/8 is 2/8 = 1/4 3/4 – 3/8 is 6/8 – 3/8 = 3/8

Calculate: (1 – 7/8) – (5/16)

Answer: (1 – 7/8) – (5/16) = 1–9/16 Find a common denominator (16), then make 7/8 = 14/16 and subtract 5/16 from 7/16, then 0from 1

Calculate: (3 – 5/8) – (2 – 13/64)

Answer: (3 – 5/8) - (2 – 13/64) = 1–27/64 Find a common denominator (64), then make 5/8 = 40/64 and subtract 13/64 from 40/64, then 2from 3

Tip Three: Multiplication To multiply fractions, first multiply the numerators, and then multiply the denominators 1/4 x 1/2 = 1/8 3/8 x 1/8 = 3/64

Calculate: 5/8 x 3/4

Answer: 5/8 x 3/4= 15/32 Multiply 5 x 3 = 15 and 8 x 4 = 32

Calculate: 7/8 x 1/2

Answer: 7/8 x 1/2= 7/16 Multiply 7 x 1 = 7 and 8 x 2 = 16

Tip Four: Division To divide fractions, switch the numerator and denominator of the second fraction, and multiply them together 3/4 ÷ 1/2 is 3/2 = 1–1/2 3/8 ÷ 1/4 is 3/2 = 1–1/2

Calculate: 3/8 ÷ 1/8

Answer: 3/8 ÷ 1/8 = 3 Flip 1/8 to 8/1 and multiply that by 3/8 to get 24/8

Calculate: 5/8 ÷ 1/2

Answer: 5/8 ÷ 1/2 = 1–1/4 Flip 1/2 to 2/1 and multiply that by 5/8 to get 10/8

Tip Five: Division – 1/2 To divide a fraction in half, leave the numerator the same, and double the denominator 3/8 ÷ 2 = 3/16 7/32 ÷ 2 = 7/64

Calculate: 5/8 ÷ 2

Answer: 5/8 ÷ 2 = 5/16 Keep 5 (numerator) the same and multiply 8 by 2

Calculate: 7/16 ÷ 2

Answer: 7/16 ÷ 2 = 7/32 Keep 7 (numerator) the same and multiply 32 by 2

Tip Six: Division by 2 (Even) To divide a mixed number in half, if the whole number is EVEN: Divide the whole number by 2 Leave the numerator the same Double the denominator 8-3/4 ÷ 2 = 4-3/8 2-3/8 ÷ 2 = 1-3/16

Calculate: 4-3/16 ÷ 2

Answer: 4-3/16 ÷ 2= 2-3/32 Divide 4 (whole number) by 2, keep 3 (numerator) and multiply 16 (denominator) by 2

Calculate: 6-7/8 ÷ 2

Answer: 6-7/8 ÷ 2 = 3-7/16 Divide 6 (whole number) by 2, keep 7 (numerator) and multiply 8 (denominator) by 2

Tip Seven: Division by two (Odd) To quickly divide a mixed number in half, if the whole number is ODD: Divide the whole number in half and write down the whole number - Let’s use 7-3/4 as an example Divide the 7 by 2 (3-1/2 ) and write down the 3 Add the numerator and denominator (3 + 4 = 7) and write the 7 as the numerator Double the denominator (2 x 4 = 8) and write the 8 as the denominator 7-3/4 ÷ 2 = 3-7/8 3-7/8 ÷ 2 = 1-15/16

Calculate: 3-1/4 ÷ 2

Answer: 3-1/4 ÷ 2 = 1-5/8 Divide 3 by 2 and write down the whole number from the answer, add 1 + 4 (numerator + denominator), then multiply 4 (denominator) by 2

Calculate: 5-3/8 ÷ 2

Answer: 5-3/8 ÷ 2 = 2-11/16 Divide 5 by 2 and write down the whole number from the answer, add 3 + 8 (numerator + denominator), then multiply 8 (denominator) by 2

Even vs. Odd Based on the whether the whole number is even or odd, remember that after dividing whole number by 2 and use one of these rules: If it’s even, leave ‘em. Leave numerator the same and double the denominator. If it’s odd, add ‘em. Add the numerator and denominator and double the denominator.

Homework Tips Always reduce (3/6 – 1/2) Always use mixed numbers (5/2 – 2-1/2) Always add the units (in., ft., lbs., etc.)