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MATH HELP AND RULES PAGE



This is the math help and rules page. You might want to make suggestions as to what rules to add. I would also like to include a glossary. Please let me know if you would like to work on this page.



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PROBLEM SOLVING STRATEGIES

Identify what you know for sure.
To begin a problem, not only do you have to identify what it is that you are trying to find out, you must identify what you know for sure and work from there. In the example below we are told that Chuck has 3 red geraniums in his garden. Knowing this allows us to calculate how many geraniums Spike has in his. Chuck's 3 geraniums + 6 (more) = Spike's 9 geraniums.
 
Geraniums
Chuck and Spike enjoy growing flowers in their gardens. Unfortunatley an early frost damaged their geraniums. Spike was left with 6 more than Chuck. Chuck, after checking the damage, realized that he had only three geraniums left. How many geraniums does Spike still have?
 




Make a Chart
Making use of a chart is often helpful in finding the solution to a problem. In the example below we are told that Chuck has 3 geraniums in his garden. All of the other characters' geranium quantities are related to each other. The following chart makes the relationships clear. Start with what you know for sure.
Gardener # of Geraniums
Chuck 3 (we were told this)
Gertrude 2XChuck(3) = 6
Samantha Gertrude(6)-4(less)= 2
Spike Samantha(2)+6(more)= 8
Geraniums 2
Chuck, Gertrude, Samantha and Spike enjoy growing flowers in their gardens. Unfortunatley an early frost damaged their geraniums. Spike was left with 6 more than Samantha. Samantha had 4 less geraniums survive than Gertrude. Gertrude had twice as many left as Chuck. Chuck, after checking the damage, realized that he had only three geraniums left. How many geraniums does Spike still have?
 





Draw a picture
Drawing pictures can be very helpful. Looking at the Geranium 2 problem below we see that we should again start with what we know for sure, that is, Chuck has three geraniums. The illustrations below the problem help show the problem's solution.
 
Geraniums 2
Chuck, Gertrude, Samantha and Spike enjoy growing flowers in their gardens. Unfortunatley an early frost damaged their geraniums. Spike was left with 6 more than Samantha. Samantha had 4 less geraniums survive than Gertrude. Gertrude had twice as many left as Chuck. Chuck, after checking the damage, realized that he had only three geraniums left. How many geraniums does Spike still have?
 
Chuck
Gertrude= 2 times Chuck = 6
Samantha = 4 less than Gertrude = 2
Spike = 6 more than Samantha = 8









Guess and Check
Sometimes a problem will not give you an obvious starting point. It will not tell you anything for sure about the characters. In these cases you may guess and then check you answer. In the problem below we know the total, but this is not enough information. If we guess that Chuck has five we then work throught the relationships. (see charts)
 
Geraniums 3
Chuck has 3 more geraniums than Fred. Fred has six less than Martha. Martha had five more than Spike, but two were stolen. If the total geraniums that they have is twenty-eight, how many geraniums does Chuck have?
 
 
Gardener # of Geraniums
Chuck 5 (a guess)
Fred 2 (3 less than Chuck)
Martha 8 (6 more than Fred)
Spike 5 ((5-2)=3 less than Martha)
Total 20 (not 28) try again


Gardener # of Geraniums
Chuck 6(a guess)
Fred 3(3 less than Chuck)
Martha 9(6 more than Fred)
Spike 6 ((5-2)=3 less than Martha)
Total 24 (not 28) try again


Gardener # of Geraniums
Chuck 7 (a guess)
Fred 4 (3 less than Chuck)
Martha 10(6 more than Fred)
Spike 7 ((5-2)=3 less than Martha)
Total 28 we're right







Use a Logic Array.
Some problems do not deal with numbers, but only with relationships. To answer these the use of a logic array (chart) can be helpful. Check off the matches. If there are no conflicts then you are correct.
 
Flowers
Fred likes the colour of flowers that is in his name. Martha likes the colour that no of the other girls like. Samantha likes the colour that Spike doesn't. Spike won't have anything in his garden that is orange. Ruggles likes her garden to match the sky. If no character has the same colour as another and the colours are Blue, Red, Orange and Yellow, match the colours with the characters.
 
 
  Blue Red Orange Yellow
Fred no yes no no
Martha no no no yes
Samantha no no yes no
Ruggles yes no no no


Since Fred likes the colour in his name , he must like Red. Therefore a no is placed beside Fred and under Blue, Orange and Yellow. Since Spike won't have anything in his garden that is orange, then he gets a no under orange and Samantha gets a yes under orange. Blue matches the sky better than yellow, so Ruggles gets blue. That leaves yellow for Martha.
 





Algebra
Algebra involves representing a number with a letter or word. Making use of algebra may help you solve problems. In the following problem Ruggles' geraniums can be represented in the following algebraic statement:
Ruggles = 40 + 2 X Martha
Replace Martha with 50
Ruggles = 40 + 2 X 50
Ruggles = 40 + 100
Ruggles = 140
 
Geraniums 4
Ruggles has 40 more than twice as many geraniums as Martha. If Martha has 50 Geraniums, how many does Ruggles have?
 





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