Fraction Basics A fraction uses 2 number to
Fraction Basics A fraction uses 2 number to represent part of a whole number. The “bottom” number is the denominator. This is the number of parts in a whole. The “top” number is the numerator. This is the number of parts of the whole you have. Example: 3 5 3 is the numerator. 5 is the denominator A “whole” is five fifths. You have just three of five, less than a whole. This is called three fifths.
There are 4 equal parts to this whole rectangle. Since 3 out of 4 are shaded in blue, we say that ¾ are shaded. There are 5 equal parts to this whole rectangle. Since 3 out of 5 are shaded in red, we say that 3/5 are shaded. There are 8 equal parts to this whole rectangle. Since 5 out of 8 are shaded in green, we say that 5/8 are shaded. We could also say that 3/8 are white.
Describe the fraction of each diagram that is shaded and the fraction that is white.
Describe the fraction of each diagram that is shaded and the fraction that is white. 5 9 is green 4 9 is white 2 5 is green 3 5 is white 1 4 is blue 3 4 is green 7 15 is grey 8 15 is white
A mixed number is a whole number and a fraction together, which shows more than one. This is 1½ one and a half. This is 13/4 one and three quarters. This is 3 1/4 three and one quarter.
A mixed number is a whole number and a fraction together, which shows more than one. This is 1½ one and a half. This is 13/4 one and three quarters. This is 3 1/4 three and one quarter.
Describe the fraction of each diagram that is shaded and the fraction that is white.
Describe the fraction of each diagram that is shaded and the fraction that is white. 23/ are purple 1/ 11/3 are purple 2/ are white. 3 3 3 are white. 34/5 are brown 1/ is white. 5
Changing a fraction to a mixed number 16 Example: / 5 is sixteen-fifths. To change to a mixed number, divide 16 ÷ 5 = 3 r. 1 which is 3 and one fifth left over, 16 or / 5 1 = 3 / 5
Convert these fractions to mixed numbers 24 6 17 3 43 9 33 4
Convert these fractions to mixed numbers 24 = 4 6 17 = 52/ 3 3 43 = 47/ 9 9 33 = 81/4 4
Changing a mixed number to a fraction 3 6 1 5 2 3 Multiply 5 x 3 = 15, PLUS 1 = 16/5 20 Multiply 3 x 6 = 18, PLUS 2 = / 3
Change these mixed numbers to fractions 1 3 4 12 2 7 5 3 2 1 12 4
Change these mixed numbers to fractions 1 2 x 12 = 24 + 1 = 25/ 3 31 4 12 7 x 4 = 28 + 3 = /7 2 2 7 5 3 7/ 29 4 x 1 = 4 + 3 = 2 1 12 x 2 = 24 + 5 = /12 4
To do operations with fractions like subtraction or addition, you need to make the denominators the same in both fractions. To change a fraction’s denominator, you must either multiply the top and bottom numbers by the same number, or divide the top and bottom number by the same number. Examples Change 3/4 into “twelfths” Change 10/15 into “thirds” 9 3 x 3 = 3 12 4 10 15 ÷ 5 = 2 5 3
Practice (12 quick fraction problems and done) 1. What fraction are white? 2. What fraction are shaded? 3. What fraction are white? 4. What fraction are shaded?
Practice (ten quick fraction problems and done) 1. 9/16 are white. 2. What fraction are shaded. 3. 5/12 are white. 4. 7/12 are shaded.
5. What fraction are green? 6. What fraction are white? 7. Convert green fraction to a mixed number. 8. What fraction are pink? 9. What fraction are white? 10. Convert green fraction to a mixed number.
5. 20/7 are green. 6. 1/7 is white. 7. 20/7 = 2 r 6, or 26/7 8. 11/8 are pink. 9. 5/8 are white. 10. 11/8 = 1 r 3, or 13/8
Change each fraction to “lowest terms”, change both numbers so that the denominator is smaller. Change this to fourths 21 28 Change this to 15 ths 26 30
Change each fraction to “lowest terms”, change both numbers so that the denominator is smaller. Change this to fourths 21 28 Change this to 15 ths 26 30 = 3 4 = 13 15
Fractions are your friends. Do homework for next week. J
- Slides: 22