INTRODUCING FRACTIONS

1 2 FRACTION WORDS The top number is called the NUMERATOR The NUMERATOR is the number of units and the DENOMINATOR is the number of parts The top number is called the NUMERATOR The bottom number is called the DENOMINATOR

Why Do We Have Fractions ? Fractions are numbers that result from dividing a length (numerator) into parts (denominator) 0_________________1__________________2 Above we have 2 units (numerator) divided into 3 EQUAL parts (denominator). The length of one part is the answer. The fraction 2/3 is spoken as “two-thirds”

Saying Fractions 1/2 Numerator = 1, Denominator = 2, we say “one-half “ 2/3 Numerator = 2, Denominator = 3, we say “two-thirds” 3/4 Numerator = 3, Denominator = 4, we say “three-quarters” 4/5 Numerator = 4, Denominator = 5, we say “four-fifths”

Unit Fractions When the Numerator of any fraction is 1 we use a special name – UNIT FRACTION The Denominator can be any number as long as the Numerator = 1. 1/2, 1/3, 1/4, 1/5, 1/6, 1/7, 1/8, 1/9, 1/10, 1/11, 1/12, 1/13, 1/14, 1/15, 1/16, 1/17, 1/18...and on and on forever ! are all Unit Fractions !

Quick Test Write down the following six words as fractions “one-half” 2. “two-thirds” 3. ”three-quarters” 4. “ two-fifths” 5. “four-sixths” 6. “five-sevenths” Write down the following six numbers as words 1/3 2. 2/5 3. 3/4 4. 3/5 5. 1/6 6. 2/7 What kind of fraction are 1/4 and 1/45 ?

Summary A fraction has a TOP number called the NUMERATOR and a BOTTOM number called the DENOMINATOR The NUMERATOR is a length divided by the DENOMINATOR into EQUAL parts. We say “thirds”, “quarters”, “fifths”, “sixths” etc When the Numerator = 1 we have a Unit Fraction.