Young Einstein Mathematics Educational Software Contents

Activity Number 259

Heading : Fraction Addition

Description : Add 2 fractions with random denominators up to 12.

Aim/Questions : Use the prompts to help work through the fraction sum. Express the answer in simplest form.

Educational software theory used:

Lets start with something simple, how we add numbers and what are some rules that we observe.

The number 234 is made up of

H        T        O

2 3 4

2     ‘Hundreds’ units,

  3   ‘Tens’ units

    4 ‘Ones units.

Eg 234 + 5

You cannot add 5 to the ‘Hundreds’ column because they are not the same units.

You cannot add 5 to the ‘Tens’ column for the same reason.

You CAN add the 5 to the ‘Ones’ units because they are the same units.

The same applies to fractions. The denominator or bottom number in a fraction is the type of units we are working with.

Halves are not the same as quarters, so you can’t directly add 1/2 + 1/4

We therefore need a way to make fractions the same type before we can add them. When both fractions have the same denominators then we can add them.

Review the sections on equivalent fractions if you are unfamiliar with converting fractions to a different denominator.

Our main rule is then to:

·   Convert both fractions to the same denominators.

Once both fractions have been converted to the same denominators we can add the amount of those units (the numerators). For example the above fraction

1/2 + 1/4 would be converted to

2/4 + 1/4

We can now add the number of quarters we have 2+1=3

The answer is written as 3/4

Educational software Instruction :

1.  Work in sections from left to right.

2.  Fill in the ‘Answer Boxes’ provided.

3.  Click the 'OK' button when finished.

Module 259 These Instructions from 'Young Einstein Mathematics educational software by Maths Practice are Copyright. Copyright Maths Practice P/L 2003 ©