Presentation on theme: "Created by Hester Sutton April 2011 The Brandywine School District presents The Singapore Math Series Session IV Fractions."— Presentation transcript:
Created by Hester Sutton April 2011 The Brandywine School District presents The Singapore Math Series Session IV Fractions
01 01/52/53/54/55/5 6/5 A fraction is a point on the number line. For example, to locate 6/5 we start at 0, find the step size so that 5 equal steps gets us to 1. Then take 6 such steps, landing at the point called 6/5.
When counting or measuring we always have some unit in mind. Example: I have 3 cups of flour. We use fractions when there is a given unit, called the whole unit, but we want to measure using a smaller unit, called the fractional unit.
Numerator is the number of fractional units. Denominator names a fractional unit by specifying how many fractional units make one whole unit. 01
Area Model Pie DiagramRectangles
0 1 Linear Measurement Model 3/4 Bar Diagrams are just thickened number lines. 3/4
Set Model If a class of 20 students contains 15 girls and 5 boys then ¾ of the students are girls.
Fractions are introduced at the end of Grade 2, but does not proceed to the next step, addition and subtraction of fractions, until Grade 4.
Comparing Fractions: With the same denominator. > Comparing the number of fractional units.
Comparing Fractions: With the same numerator. > Comparing the size of the fractional units.
Circle the smallest fraction.
Renaming Fractions ==
Mother opened a quart of milk and poured 1/5 of the quart for Kate and 2/5 for Ryan. How much was left? Quart of Milk KateRyan ? 2/5 of the quart was left.
4/5 of the children in the choir are girls. If there are 8 boys, how many children are there altogether? Children in the choir GirlsBoys x 5 = 40 There are 40 children altogether.
Peter had 400 stamps. 5/8 of them were Singapore stamps and the rest were U.S. stamps. He gave 1/5 of the Singapore stamps to his friend. How many stamps did he have left? 400 stamps Singapore StampsU.S. Stamps ? 7/8 x 400 = 7 x (1/8 x 400) = 7 x 50 = 350 Peter had 350 stamps left.
Mixed numbers and Improper fractions. Improper fractionMixed number is a whole number plus a fraction. is a fraction where the numerator is greater than the denominator.
5 children want to share 3 giant cookies equally. How much should each one get? Cookie Each child will get 3/5.
42 Children GlassesNo glasses Next calculate the number of children who wear glasses children do not wear glasses.
of the balls in a basket are green.of the balls in a basket are purple. If there are 240 balls in all, how many of the balls are neither green or purple? of the balls are neither green or purple. 240 ?
Sam has 3/7 as many stamps as Lisa. If Sam gives 1/6 of his stamps to Lisa, what will be the ratio of the number of Sam’s stamps to Lisa’s? Lisa Sam The ratio of Sam’s stamps to Lisa’s stamps is 5:15 or 1:3