Math 131

Spring 04

Hands-On Percents

 

1) Place 12 yellow tiles on the table (and no other tiles). 

What percentage of the total number of tiles on the table is yellow?

 

Now place some green tiles on the table so that the number of green tiles is 25% of the number of yellow tiles.  Place reds so that the number of reds is 75% of the number of yellows.

            How many green tiles are on the table?         

            How many red tiles are on the table?

            What percentage of the total number of tiles on the table is yellow?

 

Add one blue tile to the table.

            What percentage of the tiles is blue?

            What percentage is yellow?

            What percentage is red?

            What percentage is green?

 

2) Place 10 green tiles on the table.  Now place blue tiles on the table so that the number of blue tiles is 50% more than the number of green tiles.  Fill in the blanks:

            Number of blue tiles on the table ____

            The number of green tiles is ______ % of the number of tiles on the table

            The number of blue tiles is _______ % of the number of tiles on the table

            The number of green tiles is _______% of the number of blue tiles

            The number of blue tiles is _______ % of the number of green tiles

 

3) Place 16 blue tiles in a pile.  Make a pile of green tiles that has 25% more tiles in it than the pile of blue tiles. 

            How many tiles are in the green pile?

 

Now make a pile of yellow tiles that has 25% fewer tiles than the green pile.

            How many tiles are in the yellow pile?

           

The number of green and the number of yellow tiles should not be the same.  If you got the same number, go back.  Look carefully  what is the “whole” in each problem?  Explain why the number of green tiles is different from the number of yellows.

 

 

Complete:

            The number of green tiles is _____ % of the number of blue tiles.

            The number of yellow tiles is _____ % of the number of green tiles.

 

           

4) Here are some clues; find out what combination of tiles satisfies them all:

                        50% of the tiles on the table are red.

                        The number of yellows is 25% the number of blues.

                        The number of greens is 125% the number of blues.

                        There are 2 yellow tiles.

 

5) Another puzzle:

                        There are 100% more blues than greens.

                        The number of yellows is 200% of the number of greens.

                        The number of reds is 25% less than the number of yellows.

                        There are fewer than 15 tiles on the table.

 

 

6) Now make up a puzzle of your own.  You will exchange your puzzle with another group of students.  Make your puzzle hard enough so the other group will have to struggle with it, but make it so they should be able to solve it before the end of class.

 

 

 

 

Cuisinaire Rod Puzzles

 

7) Which of the following statements are true?

 

            The length of the purple rod is 50% of the length of the brown rod.

            The length of the brown rod is 50% of the length of the purple rod.

            The purple rod is 50% shorter than the brown rod.

            The brown rod is 50% longer than the purple rod.

            The length of the brown rod is 100% more than the length of the purple rod.

            The length of the brown rod is 200% more than the length of the purple rod.

            The length of the brown rod is 200% of the length of the purple rod.

 

8) Answer the following (hint: at least one of these is a “trick question”):

            If the blue rod represents 15% of a whole, what combination of rods could represent the whole?

            If brown represents 100%, what does light green represent (as a percentage)?

            Which rod or rods represents 300% more than the red rod?

            Which rod or rods represents 300% of red?

            Which rod or rods represents 90% less than orange?

            Which rod or rods represents 100% less than orange?

            Which rod or rods represents 200% more than orange?

            Which rod or rods represents 200% less than orange?

 

Copyright 2005, Debra K. Borkovitz.  You may copy or edit this material for non-profit, educational use only.

 

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