Elaine Posted September 10, 2008 Share Posted September 10, 2008 We can't figure this out- Adam bought a pen. He also bought a book which cost 3 times as much as the pen. He spent $112 altogether. Find the cost of the book. Are we just really dumb? Quote Link to comment Share on other sites More sharing options...
Jean in Newcastle Posted September 10, 2008 Share Posted September 10, 2008 Divide the $112 by 4. (The book is 3 parts of the total, the pen is 1 part). Quote Link to comment Share on other sites More sharing options...
Alana in Canada Posted September 10, 2008 Share Posted September 10, 2008 Use the rectangle "diagram". It represents the total $112.00 Then the pen is one unit (section off the box)--and the book is three of the same sized units. There are a total of four units: so just divide 112 by 4. The first time we saw one of these I was thrown for a mini-loop, too. The diagram was a great way to help explain it to ds. I hope that was clear! Quote Link to comment Share on other sites More sharing options...
Sputterduck Posted September 10, 2008 Share Posted September 10, 2008 84 I think Quote Link to comment Share on other sites More sharing options...
Elaine Posted September 10, 2008 Author Share Posted September 10, 2008 Thank-you! Don't I feel like a big moron.:tongue_smilie: Quote Link to comment Share on other sites More sharing options...
Kate in Arabia Posted September 10, 2008 Share Posted September 10, 2008 Singapore is big on setting up bar/graphs, we use the term "segments": pen = 1 segment book = 3 times as much as the pen, so 3 segments he spent $112 altogether, and altogether has 3+1 = 4 segments; so divide 112 into 4 segments: 112/4 = 28 so each segment is 28, therefore: pen = 1 segment = $28 book = 3 segments = 3x28 = $84 Quote Link to comment Share on other sites More sharing options...
Jean in Newcastle Posted September 10, 2008 Share Posted September 10, 2008 Don't feel like a moron! I've been stumped many times by problems like that! Quote Link to comment Share on other sites More sharing options...
ljf Posted September 10, 2008 Share Posted September 10, 2008 I get $84. (cost of pen) + (cost of book) = $112 (cost of pen) + 3*(cost of pen) = $112 4*(cost of pen) = $112 (cost of pen) = $28 (cost of book) = $112 - (cost of pen) (cost of book) = $84 Quote Link to comment Share on other sites More sharing options...
Jenn in Mo Posted September 10, 2008 Share Posted September 10, 2008 That is one expensive book. Quote Link to comment Share on other sites More sharing options...
Elaine Posted September 10, 2008 Author Share Posted September 10, 2008 That is one expensive book. :lol: Quote Link to comment Share on other sites More sharing options...
dawn of ns Posted September 10, 2008 Share Posted September 10, 2008 That is one expensive book. He's taking a caligraphy course. He had to buy a good quality fountain pen and the text for the course.:001_smile: Quote Link to comment Share on other sites More sharing options...
WTMindy Posted September 10, 2008 Share Posted September 10, 2008 Don't feel dumb! Singapore teaches a different way to think about math problems. That is one thing I really like about it!! There are times when I am stumped at how to set up a diagram and I was a math major. I have to solve the problem algebraicly and then go back and figure out how to set up the bars. But, I would encourage you to practice on those bar problems because they get harder and harder, but they allow students to do complicated mathematical problems without needing to know algebra yet. Good stuff!! Quote Link to comment Share on other sites More sharing options...
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