May I know how to show working for a P5 student? Thanks

Replies
21

Kai Meng

The average is between the two fractions.

4 years ago

Sherleen Ee

Taking average is 9/20, not the ans for this qn as denominator must b lesser than 20.

4 years ago

Kai Meng

It says not greater than 20, doesn't mean less than 20.

4 years ago

Kai Meng

20 is not greater than 20.

4 years ago

Emma Valerio

4 years ago

Eugene Ng Ming Teck

This question is not about average. It is about equivalent fractions.
You want a fraction bigger than 2/5 but smaller than 1/2. But you cannot compare the fractions until the denominators are the same.

4 years ago

Eugene Ng Ming Teck

Emma has solved it well. Thank you

4 years ago

Kai Meng

The average of two numbers is always between them.

4 years ago

Eugene Ng Ming Teck

Thanks Kai Meng, that is true indeed. What I intended to explain was in the context of a P5 student. And not to layer 2 different concepts together. But it would be good to extend this for pupils who have a good grasp of math.

4 years ago

Kai Meng

I'm for integrating concepts, as I find that many students see the topics as separate and that limits their understanding and problem solving skills in some ways. Anyway there are always multiple ways to answer a question.

4 years ago

Sherleen Ee

ok.... got it.... thanks alot

4 years ago

Sherleen Ee

But what if the qn want a denominator lesser than 20?

4 years ago

Kai Meng

Then that's impossible because 9/20 is already at its simplest form.

4 years ago

Sherleen Ee

I roughly work out... I thought 3/7 is psb? (if qn wants denominator less than 20)

4 years ago

Kai Meng

3/7 can be an answer if "between" doesn't mean right in the middle between those two given fractions.

4 years ago

Emma Valerio

There would be other options, if the answers could be given as decimals: 0.41, 0.42...0.49

4 years ago

Emma Valerio

3/7 does answer the original question. It does not say the answer has to be right in the middle. Neither does it say that there is only one answer. How did you find 3/7 and how would you explain that to a child?

4 years ago

Sherleen Ee

Thanks alot for your explanation, appreciate it much :)

4 years ago

Kho Tek Hong

Many possible answers: 3/7, 4/9, 5/11, 5/12, 6/13, etc. get students to justify their answers.

4 years ago

Rika Gerryts

Or 5/12

4 years ago

Darryl Seah

Key question to the child: "Why did you choose this fraction?"