Adding Fractions

Objectives

To use visual aids for adding fractions with a common denominator.

Resources

Abacus 4 Textbook 3 | Copier or squared paper | Fraction calculations (MyMaths)

Today's Lesson

Main Activity

For the mental warm up, call out some fractions ‘over 100’ (with 100 as the denominator – that is, they are all hundredths). Ask your student what the decimal equivalent would be.

For example:

Thirty four hundredths or 34/100 = 0.34

Seventy seven hundredths or 77/100 = 0.77

Turn to page 79 in Abacus 4 Textbook 3.

Either copy the page or allow your student to write directly in the textbook.

Look at the fractions and point out to your student that all of the bottom numbers (denominators) are the same for each question. This makes the calculation very easy. Run through the activities in Sections 1, 2 and 3 of Fraction calculations (MyMaths) if needed.

Look at the first pizza and ask your student to count the slices - there are six. Point out that the denominator for the related questions is therefore 6 as the pizza has been divided into sixths: 1/6, 2/6, and so on.

Ask your student if you were to eat three slices, how much would be left as a fraction of the original pizza?

Look at the first question and draw attention to the top numbers (numerators). You have been asked to add the two fractions. As long as the denominators are identical, it is just a matter of adding the numerators together. The denominator in the answer will remain the same. It might be easier to understand this by saying them aloud, for example, two sixths plus three sixths equals five sixths.

Once your student is comfortable with the concept, ask them to complete the page independently.

Citations

[1] app.mymaths.co.uk