Add on fractions with the same denominator | Maths | Quizalize & Oak National Academy

Starter quiz

Which of these definitions describes a total?

A number added to another number.

All of the parts added together. ✓
What is the missing number in this bar model?

'5' ✓
What addition is being shown by this number line?

4 + 1 = 5

1 + 4 = 5 ✓

4 = 5 + 1

1 = 5 + 4
A bag of marbles contains 9 marbles. What fraction of the total is each marble?

$\frac{2}{8}$

$\frac{1}{8}$

$\frac{1}{9}$ ✓

$\frac{2}{9}$
What is the missing number in this bar model?

1 ✓

5

6
What is true of the numerator and denominator of a fraction if the fraction is equivalent to one whole?

They add together to make 1

They are always both 1

They are the same. ✓

Exit quiz

Look at the picture. What is the unit of this addition?

Ones

Wholes

Strawberries ✓
Look at the image. What is the missing label marked with a question mark?

addend ✓

sum

part
What addition is being represented on this number line?

$\frac{1}{8}$ + $\frac{4}{8}$ = $\frac{3}{8}$

$\frac{1}{8}$ + $\frac{3}{8}$ = $\frac{4}{8}$ ✓

$\frac{6}{8}$ + $\frac{5}{8}$ = $\frac{1}{8}$

$\frac{3}{8}$ + $\frac{3}{8}$ = $\frac{6}{8}$
What is the sum of this equation? $\frac{2}{7}$ + $\frac{4}{7}$ = ___

$\frac{6}{14}$

$\frac{8}{7}$

$\frac{6}{7}$ ✓
What is the correct sum for this equation? ___ = $\frac{4}{15}$ + $\frac{6}{15}$

$\frac{10}{30}$

$\frac{10}{15}$ ✓

$\frac{15}{30}$
Which equation matches the problem? A sunflower is two-tenths of a metre tall. Over a month, it grows four-tenths more. How tall is the sunflower now?

$\frac{2}{10}$ + $\frac{4}{10}$ = $\frac{10}{10}$

$\frac{2}{10}$ + $\frac{6}{10}$ = $\frac{4}{10}$

$\frac{2}{10}$ + $\frac{4}{10}$ = $\frac{6}{10}$ ✓

Worksheet

Loading worksheet ...

Presentation

Loading presentation ...

Video

Lesson Details

Key learning points

If fractions have the same denominator they can be added on.
If 2 plus 3 is equal to 5 then 2 one sevenths plus 3 one sevenths is equal to 5 one sevenths.
To add fractions with the same denominator you use the language of unitising.

Common misconception

When adding fractions with the same denominator many children may try and add both the numerator and denominator.

This is a misunderstanding of the unitisation. Practise counting in different set of objects such as cubes, counters, children. Move children on to counting in fractions and explain that this is simply a different unit, shown by the denominator.

Keywords

Units - The unit is one of something that defines the ‘one’ you are counting in.
Denominator - A denominator is the bottom number in a fraction. It shows how many parts a whole has been divided into.
Numerator - A numerator is the top number in a fraction. It shows how many parts we have.