# Addition and Subtraction of Proper Fractions with Same or Different Denominators

- Author:
- สุดารัตน์ ไตรยวงค์

- Topic:
- Addition, Fractions, Subtraction

Aim of Applet
This applet illustrate the addition and subtraction of proper fractions of different denominatiors.
The need to make up equivalent fractions with same denominators before we can add the numerators and get the resulting fraction is visually demonstrated.
The resulting fraction may also need to be reduced to the lowest term where necessary
Interactive elements (checkboxes and sliders)
Use the
1. Subtract Fraction checkbox to activate the operation of subtraction of proper fractions in the applet.
2. numerator & denominator sliders to change the values of the two proper fractions.
3. FractionSlider checkbox to show the numerator & denominator sliders for the two fractions to be added/subtracted.
4. EquivalentFraction checkbox to reveal more diagrams and illustrate concept of creating equivalent fractions for adding subtracting fractions with a common denominator.
5. Evaluate Result checkbox to show the arithmetic operations of the equivalent fractions and the resulting fraction in its lowest terms.
6. ShiftCircleLeftRight slider to shift blue circle towards red circle on the right!
7. MixedNumberResult slider to show the resulting fraction in mixed number format.
7. DetachPie slider to show visually the resulting fractions from
(i) addition of proper fractions resulting in proper fractions, improper fraction or mixed numbers.
(ii) subtraction of proper fractions resulting in remaining proper fractions or negative fractions.
Prior knowledge of pupils
1 Pupils know the terms fraction, proper fractions, improper fractions, whole and mixed numbers
2. Pupils know addition and subtraction of whole numbers and proper fractions of same denominator
3. Pupils know idea of equivalent fractions
4. Pupils may or may not know the idea of lowest common multiple, but are be able to grasp the visual idea of having fraction parts of the same size and hence the concept of equivalent fractions of the same/common denominator

Questions for Learner :
1. How do we add two fractions of the same/common denominator ?
2. Explain the idea of equivalent fractions
3. How do we add two fractions with different denominators ?
4. How do we find the "right" number of parts to split, so that the parts
in both fractions are of the same size ? (From this we get
the same/common denominator for both fractions)