Report

Aims of session • • To explore the language and skills learnt in Rushen Primary School relating to fractions. To show methods of division used in Rushen Primary School. Fractions - what are they? Part of a whole. 1 2 A number written with the top part (the numerator) telling how many you have. and the bottom part (the denominator) telling you how many parts the whole is divided into, Language of fractions • • Language of fractions is used all around children, “here’s my half.” “I’ll cut this cake into equal parts for the four of us.” etc We would encourage correct use of terms from early on - not “my half is bigger than yours!” Simple fractions Simple fractions are the common fractions such as 1 1 1 1 1 1 2 3 4 5 8 10 Equivalent fractions • Equivalent fractions are fractions that are equal in size but have a different denominators or numerators. 1 2 = 2 4 There are many more, use of fraction wall. Mixed Numbers & Improper fractions Mixed numbers and improper fractions show values where there are more than one whole being shown. Two and a half pieces is the same as 5 halves. 2 1 2 = 5 2 Changing fractions to a common denominator When fractions are to be ordered or added than they need to have the same denominator (link to equivalent fractions) 3 1 1 1 7 4 8 2 4 8 becomes 6 1 4 8 8 8 2 8 7 8 8 is the common denominator as all denominators are in the times table. If this is not obvious then multiply the denominators to find a common denominator. Ordering fractions To order fractions of the same denominator we need to look at the numerator. 6 1 4 3 7 8 8 8 8 8 Smallest to largest 1 3 4 6 7 8 8 8 8 8 Ordering fractions To order fractions with different denominators we need to convert all fractions to the lowest common denominator. 3 1 1 1 7 4 8 2 4 8 becomes 6 1 4 8 8 8 2 7 8 8 7 Smallest to largest 1 2 4 6 7 and then 1 1 1 3 8 8 8 8 8 8 4 2 4 8 Ordering fractions Finding fractions of an amount or quantities. As a fraction is a division of a whole then we use division to find a fraction of amounts. Finding a half means dividing by 2 - to make two equal sized groups. 1 4 ÷4 1 ÷ 3 1 ÷ 5 3 5 ie divide by the denominator. Finding fractions of an amount or quantities. To find fractions such 2/3 then we need to find a third and then multiply this by 2. 2 of 12 = 1 3 3 is 4 x 2 = 8 Finding fractions of an amount or quantities. To find fractions such 2/3 then we need to find a third and then multiply this by 2. 2 of 12 = 1 3 (12 ÷ 3) is 4 then x 2 = 8 3 Divide by denominator and then multiply this by the numerator. Methods of Division HTU by U • • Words linked to division - group, divide, division, divided by, divisible, factor, share, half, remainder. Need to know division facts - related to times tables knowledge. Formal method 196 ÷ 6 Methods of dividing HTU by TU Repeated subtraction 972 ÷ 36 Formal method 972 ÷ 36