Transcript Middle Focus Group 1 Sept

Maths Focus Group
September 1st 2010
Dotty Pairs Game
• You need two sets of cards 1-6 or dice
• The children play in pairs. One child takes dots, the other
takes crosses.
• The players take turns turning over two cards or roll the dice.
The numbers are used to form a fraction e.g 2 and 5 are
turned over - could make two fifths or five halves.
• One fraction is chosen and marked on a 0-6 number line with
the players identifying mark.
• Winner is the person who can get three uninterrupted marks
on the number line.
• If a fraction is already marked on the number line the player
misses that turn.
0
1
2
3
4
5
6
Diagnostic Question – Stage 5
Four students all buy the same sized cake.
Jill eats two sevenths of her cake.
Jack eats two ninths of his cake.
Mere eats two elevenths of her cake.
Hemi eats two thirteenths of his cake.
Who eats the most?
What answers will you get and why?
Diagnostic Question – Stage 6
Mandy bought a bag of apples containing 12
apples. She ate one quarter of the apples.
How many did she eat?
What knowledge will students need to find the
answer?
Implications?
Problem of ‘out of’
• How does viewing fractions as ‘out of’ lead to
misconceptions?
The problem with “out of”
1
2 +
2
3
8
6
2
3
3 = 5
x 24 =
“I ate 1 out of my 2
sandwiches, Kate ate 2 out
of her 3 sandwiches so
together we ate 3 out of the
5 sandwiches”!!!!!
2 out of 3 multiplied by 24!
= 8 out of 6 parts!
Fraction Language
Use words first then introduce symbols with care.
e.g. ‘one fifth’ not 1/5
How do you explain the top and bottom numbers?
The number of parts chosen
1
2
The number of parts the whole has been
divided into