A blog about Mathematics and Mathematics Education in Singapore, as well as Mathematics Education in general. Written for students, parents, educators and other stakeholders in Singapore, and around the world.
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Tuesday, March 3, 2015
[Pri20150302FCW] The Cost of Fish and Chicken
The ratio of the cost of fish to that of chicken is
1.5 : 1 or 3 : 2. I choose this nice
whole number ratio and write them in triangle units. You can choose draw any shape you want to
surround the ratio unit actually.
Multiplying by 3 and by 4 (the numerical dollar costs), we obtain 17
triangle units equal to 76.50. From here
we can divide by 17 to get the equivalent of 1 triangle unit, and then multiply
by 3 to get the equivalent of 3 triangle units.
Ans: 1 kg of fish costs $12.50
Once again my Ratio Units method solves this problem quickly
and you can use this method to also present the answer in a matter that even
the teacher who is marking this can understand J.