» grade6 http://singaporemathsource.com All about the world's best math...And how to use it! Singapore Math Training, Tips and News Fri, 18 May 2012 15:45:50 +0000 en hourly 1 http://wordpress.org/?v=3.3.2 Grade 6 Word Problem Solutions http://singaporemathsource.com/word-problem-solutions/ http://singaporemathsource.com/word-problem-solutions/#comments Mon, 25 May 2009 01:54:09 +0000 Cassy http://smartt.wordpress.com/?p=765 Earlier this month, I posted the following problem from a Nanyang Primary School 2007 Preliminary Examination I found at MissKoh.com:

A mixture, weighing 100 kg is made up of 2 chemicals A and B in the ratio of 7:3. When some volume of Chemical A evaporates, the content of Chemical A is reduced to 60% of the new mixture. What is the mass of the mixture now?

I thought I’d share how my son worked the problem:

chemical wp

He knew that if he multiplied 40% x 2.5, he’d get 100% so:

2.5 x 30 kg = 2.5 x 40%

75kg = 100%

I used a different drawing for “after” :

chem after

How did you solve the problem?

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