Activities/Abacus/Worksheet

Fractions

The Fraction abacus

Start Abacus ,

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?

To show that the solutions which use more than one string are correct, use the Lowest Common Denominator (LCM) 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

The Caacupé abacus

Load the Caacupé abacus

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?

see the answersheet