Monday, October 20, 2008

Singapore Math 2

Continuation from previous post.

This is also from P5 Challenging Math, Unit 1. It's a Challenge question where the solution doesn't show workings. The book's answer was 33, which is different from Brian's answer. Please let us know which answer is right, thanks; and also if the model is drawn correctly.

In a school, there are 45 more students in Primary 5 than in Primary . In Primary 4, there are 18 more girls than boys. There are 12 more boys in Primary 5 than in Primary 4. How many more girls than boys are there in Primary 5?

Solutions may be sent to mathsingapore at gmail dot com. Thanks!


monlim said...

Just a quick note, very important in models is that each part has to be of equal value (go back to my 3 assumptions). I think that's where you and Brian stumble - if you manage to stick to that concept, you'll manage to get it.

PS I think the answer given for the first question is wrong. I got 39 too.

Lilian said...

I told you "we" need intensive tuition; I did tell him to always break down to basic equal unit; but sometimes just can't see it. I think the foundation is just missing.

Anonymous said...

yay, I got 39 too!!

Ans emailed to