Fractions Peter Gibby Whats a Fraction A fraction

Fractions Peter Gibby

$What’s a Fraction? • A fraction is like a decimal because its between whole$

What’s a Fraction? • A fraction is like a decimal because its between whole numbers, the difference is that it can be of a different base, instead of just 10. • We get a fraction by dividing a small number by a larger one. • The simplest is probably ½ or one half.

$A Fraction • A decimal is a type of fraction but is only in$

A Fraction • A decimal is a type of fraction but is only in forms of tens, like 1/10, 1/100 • Fractions let us express some values more easily. Would you rather write “ 0. 5714285712” or “ 4/7”? • The top number is called the “numerator, ” and the bottom is called the “denominator”

$Adding like Denominators • Adding fractions with like denominators is just adding the numerators$

Adding like Denominators • Adding fractions with like denominators is just adding the numerators then adding the denominator at the end. • 1/6+3/6=4/6 • 2/5+3/5=5/5 • Fractions, like decimals can be added together and get a whole number. The denominator represents how many pieces are needed to make a whole, and the numerator is the number of pieces. So 2/2=3/3=4/4=5/5=1

Subtracting like Denominators • This is just the same as adding, but we subtract instead. • 6/8 -3/8=3/8 • 11/12 -1/12=10/12 • Something else we can do is simplify fractions. We can do that by dividing the numerator and denominator by the same number. Take 10/12 for instance, we can divide both by 2 for 5/6.

$Checking for Equality • Because we can simplify fractions, there are infinite ways to$

Checking for Equality • Because we can simplify fractions, there are infinite ways to express each value. How can we determine if they are the same? • One way, is cross multiplying. We multiply the numerator of the first and the denominator of the second, then just the opposite. If they values are equal, than so are the fractions.

Equality • Lets start off with some we can already know: • 2/2 and 5/5, 2 x 5=10 and 2 x 5=10, they must be equal. • 1/3 and 2/6, 3 x 2=6 and 1 x 6=6, they must be equal. • 2/5 and 4/11, 5 x 4=20 and 2 x 11=22, they must not be equal • 1/123 and 4/492, 123 x 4=492 and 1 x 492=492, they must be equal.

Why Equality is Important • If you want to add two numbers, but they don’t have the same denominator, you could try to find equal fractions that have the same denominator • 2/4+3/8=4/8+3/8=7/8 • 2/16+7/8=1/8+7/8=8/8=1 • 1/14+1/7=1/14+2/14=3/14