Let's solve each fraction word problem step by step.
---
Problem 1:
A classroom has 30 chairs, one third are white in colour. How many are white coloured chairs?
#### Solution:
1. We know the total number of chairs is 30.
2. One-third of the chairs are white. To find one-third of 30, we calculate:
\[
\frac{1}{3} \times 30 = \frac{30}{3} = 10
\]
#### Answer:
\[
\boxed{10}
\]
---
Problem 2:
Anne reads a book of poems which are of 21 pages. She finished reading two-thirds of the book on Sunday. How many pages are left to read?
#### Solution:
1. The total number of pages in the book is 21.
2. Anne read two-thirds of the book. To find two-thirds of 21, we calculate:
\[
\frac{2}{3} \times 21 = \frac{2 \times 21}{3} = \frac{42}{3} = 14
\]
So, Anne read 14 pages.
3. To find the number of pages left to read, subtract the pages she read from the total pages:
\[
21 - 14 = 7
\]
#### Answer:
\[
\boxed{7}
\]
---
Problem 3:
Susan's sausages sells half of their sausages at 9 am. She has 12 left. How many did she sell then?
#### Solution:
1. Let the total number of sausages Susan had initially be \( x \).
2. She sold half of them, so she has the other half left. According to the problem, she has 12 sausages left, which represents half of the total:
\[
\frac{x}{2} = 12
\]
3. To find \( x \), multiply both sides of the equation by 2:
\[
x = 12 \times 2 = 24
\]
So, Susan initially had 24 sausages.
4. Since she sold half of them, the number of sausages sold is:
\[
\frac{24}{2} = 12
\]
#### Answer:
\[
\boxed{12}
\]
---
Problem 4:
Uncle Tom had two-thirds of a 12-slice pizza. How many slices did Uncle Tom eat?
#### Solution:
1. The total number of slices in the pizza is 12.
2. Uncle Tom ate two-thirds of the pizza. To find two-thirds of 12, we calculate:
\[
\frac{2}{3} \times 12 = \frac{2 \times 12}{3} = \frac{24}{3} = 8
\]
#### Answer:
\[
\boxed{8}
\]
---
Final Answers:
1. \(\boxed{10}\)
2. \(\boxed{7}\)
3. \(\boxed{12}\)
4. \(\boxed{8}\)
Parent Tip: Review the logic above to help your child master the concept of 3rd grade fraction word problems worksheet.