Worksheet
Suggested for school years 6 - 8
Start Abacus Abacus-icon.png,
select the Fraction abacus.
Slide one of the 1/2 beads to represent 1/2
Another way to represent 1/2 is to slide half of another string of fraction beads, for example, slide 2 of the 1/4 beads. That is (2 x 1)/4 = 2/4 = 1/2
How many ways can you make 1/2, remember you can use 2 strings eg. 1/3 + 1/6 = 1/2
If using just one string, only some of the strings of beads can be used to make 1/2. Which ones? Why?
Show that the solutions which use more than one string are correct, use the Lowest Common Denominator LCD method, for example for the case of 1/3 +1/6 = 1/2 1/3 + 1/6 = 2/6 + 1/6 = (2+1)/6 = 3/6 = 1/2
How do you know if you have found all the solutions?
Find all the ways to make 1/3 and 2/3
Draw your solutions as pie charts, you can use Paint, TurtleArt, Socialcalc or Gnumeric in Gnome.
1on2piedraw.jpg | Fractionpieturtle.jpg | Fractionpiesocialcalc.jpg
The Caacupé abacus Load the Caacupé abacus Abacuscaacupe.jpg
It can represent negative whole numbers and fractions. 1/2 can be represented as 10 - 9 - 2/3 + 1/6
How many different ways can you represent 1/2, 1/3, 2/3
How do you know when you have found them all?
Similar to the Pie chart, can you think of a way to visually represent the addition of positive and negative fractions?
see the answersheet
