# lee's classroom

## (another MPPS global2.vic.edu.au weblog) # Application For Today’s Maths Lesson: Addition and Subtraction of Fractions continued

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• Ryan was ¾ of the way through measuring the running track and he had measured 75 metres.  How long will the running track be?  (Show your thinking with a diagram and your mathematical working out.)
• Jude wanted the class to work on their writing for ¾ of an hour.  How many minutes is that? (Prove your thinking by showing it on a clock.)
• Griffin was asked to buy 6 metres of rope for his dad.  When his dad had used the rope to tie up the trailer, he had 50 cm leftover.  What fraction of the rope did he use? (Record using the four headings: Diagram/Table, Maths/Number, Solution Sentence, Explanation & Reasoning)
• Mum bought 3 kg of flour to make cupcakes for Sammy’s birthday.  She used all of the flour except 200g.  What fraction of the flour was left over? (Record using the four headings: Diagram/Table, Maths/Number, Solution Sentence, Explanation & Reasoning)
• The cyclists had completed 5/6 of the course in 42 minutes.  At this rate, how long would it take them to complete the course? (Record using the four headings: Diagram/Table, Maths/Number, Solution Sentence, Explanation & Reasoning)
• The swimming relay team times were 1 ½ minutes, ¾ minute, 1 ¾ minutes and 2 minutes.  What was the overall time that the relay team took? (Record using the four headings: Diagram/Table, Maths/Number, Solution Sentence, Explanation & Reasoning)
• Explain two different operations that might be used to solve the problems above.  Why do you think this is?

More Practice:

Group 1

Using rectangular models (see resource folder) sheet. Students cut up models as needed for subtraction.  1- 1/5, 1- 1/9, 1- 1/10, 1-5/6, 1-3/7,

2- ½, 3- 1/3, 3- 1/8
Group 2

Students are given 9/5. They are to convert this to a mixed number and record their answer.

Students are given 3 and 7/10. They are to convert this to an improper fraction and record their answer.

They are to add the two fractions together (in whatever form they prefer), recording the equation and their working out.

Why did/ didn’t you make the denominators the common?

How did you know to make all of the denominators tenths? Students simplify the answer if they have not already done so. Have students find the difference between the two fractions, recording the equation and their working out.

What does the difference mean? Why did you write this fraction first?

Have students write a word problem that includes the two fractions.   EXTEND BY changing the given improper and mixed numbers.

Group3

1/5 +3/10, 3/6 + 6/12, 2/9 + 1/90,

4/5 – 2/10, 5/8 – ¼, 7/9 – 1/27

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