Fractions

Quick wits – Week Three

By the end of this week’s lessons, you will be able to: Write a fraction in its simplest form Convert mixed numbers to improper fractions Calculate fractions Calculate a fraction of a quantity

Fractions & Decimals To turn fractions into decimals and decimals into fractions we need to remember column names Thousandths Hundreds Tens Units Tenths Hundredths 000.000

0.03 0.5 Decimals & Fractions is 3 hundredths is 5 tenths 3 100 5 10

0.12 0.01 Decimals to Fractions is 1 hundredth 12 is 12 hundredths 100 Tenths 12 100 0.12 is 12 hundredths Tenths Hundredths 1 100 0.01 is 1 hundredth

Equivalent fractions

Simplifying fractions It is often best to have the numbers possible when we write fractions 12 20 3 5 Instead of we would have We have cancelled the fractions down, by dividing top and bottom numbers by the same number (in this case 4)

15 35 3 7 = Divide by 5 24 36 2 3 = Divide by 12 55 66 5 6 = Divide by 11

Number of parts chosen Total number of parts How to change a mixed number to an improper fraction: Fraction notation How to change a mixed number to an improper fraction: Number of parts chosen Total number of parts

Finding Fractions of Amounts 2 7 If you are asked for of an amount 1 7 2 7 Find by dividing by 7 and then find by multiplying by 2. 2 7 To find of 35: 35 ÷ 7 = 5 5 x 2 = 10 2 7 of 35 is 10

Finding Fractions of Amounts 5 9 If you are asked for of an amount 1 9 5 9 Find by dividing by 9 and then find by multiplying by 5. 5 9 To find of 63: 63 ÷ 9 = 7 5 x 7 = 35 5 9 of 63 = 35

Finding Fractions of Amounts A quick way to remember what to do is: “Divide by the bottom, times by the top”

Finding fractional amounts Apply skills and knowledge to find fractional amounts

Break time

An improper fraction is when the ‘numerator’ is bigger than the ‘denominator’. 5 9 7 4 12 15 12 10

How to change a mixed number to an improper fraction: 1 3 7 4 Whole number (1) x Denominator (4) + Numerator (3) = 7 7 becomes the numerator The denominator stays the same as in the mixed number, in this case 4.

How to change a mixed number to an improper fraction: 2 4 14 5 Whole number (2) x Denominator (5) + Numerator (3) = 14 14 becomes the numerator The denominator stays the same as in the mixed number, in this case 5.

Now you know the rule, let’s just use numbers: 3 3 24 7 3 x 7 3 + = 24

Adding and subtracting fractions make sure the bottom numbers are the same by finding a common denominator. add or subtract the numerators (top numbers). Put your answer over the common denominator you found in step one. simplify the fraction if needed + + 5 8 3 16 5 8 2 5

Multiplying fractions Multiply the numerators Multiply the denominators simplify the fraction if needed 5 8 3 8 2 5 3 4 1 2 1 4 1 2 x x x

Dividing fractions - KFC K – keep the first fraction F - flip the fraction you C -change division sign for multiplication Then proceed as you would for multiplying fractions… Multiply the numerators Multiply the denominators simplify the fraction if needed

Dividing fractions - KFC 2 3 4 5 3 4 1 2 1 3 3 4 3 2 ÷ ÷ ÷

Applying skills

Individual study Developing skills