Adding fractions with different denominators

Maths, Grade 6. Practice set 3. About 15 minutes.

Reading options: text size, colours, spacing, read aloud

Read-aloud buttons use your device's own voice. They work without internet only if your device has an offline voice installed.

Your answers are saved on this device only.

Answer each question, then press Check answer. If you are stuck, open the hint. You can try again as many times as you like.

8 questions. 0 answered correctly so far.

Part 1: Find a common denominator

Question 1 of 8

What is 1/2 + 1/4?
Hint

Change 1/2 into quarters first.

Explanation

1/2 is the same as 2/4. Then 2/4 + 1/4 = 3/4. We add the tops (numerators) only after the bottoms (denominators) are the same.

Question 2 of 8

Which number is a common denominator for 1/3 and 1/4?
Hint

Look for a number that both 3 and 4 divide into with nothing left over.

Explanation

12 works because 3 x 4 = 12 and 4 x 3 = 12. Adding the denominators (3 + 4 = 7) is a common mistake.

Question 3 of 8

Hint

Use 12 as the denominator. How many twelfths is 1/3? How many twelfths is 1/4?

Explanation

1/3 = 4/12 and 1/4 = 3/12. So 4/12 + 3/12 = 7/12.

Part 2: Simplify your answer

Question 4 of 8

Hint

Find a number that divides both 6 and 8.

Explanation

Both 6 and 8 can be divided by 2. 6 / 2 = 3 and 8 / 2 = 4, so 6/8 = 3/4.

Question 5 of 8

Hint

1/3 is the same as 2/6.

Explanation

1/3 = 2/6. Then 1/6 + 2/6 = 3/6, and 3/6 simplifies to 1/2.

Question 6 of 8

Which of these are equal to 1/2? Choose all that are correct. (Choose all that are correct.)

Explanation

2/4 and 5/10 both have a top that is exactly half of the bottom, so they equal 1/2.

Part 3: In real life

Question 7 of 8

Hint

This is the same sum as question 1.

Explanation

1/4 + 1/2 = 1/4 + 2/4 = 3/4 of the bottle.

Question 8 of 8

Model answer

You cannot add the bottoms. 1/2 + 1/3 = 3/6 + 2/6 = 5/6, which is more than 1/2, but 2/5 is less than 1/2.

Finished?

0 of 8 answered correctly.