6.2+Using+Rules+of+Thumb+-+2010-2011

S.L 1/23/11

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**Big Idea:** //Many important practical and mathematical applications involve comparing quantities of one kind or another; it is important to know which method to use and how we should use them.// ====== = Problem 6.2 = Using Rules of Thumb


 * A) //It takes about 100 maple trees to make 25 gallons of maple syrup. Mr. Paulo made maple syrup from all of his sugar maple trees. He ended up with 16 gallons of syrup. About how may sugar maple trees does he need?//**
 * 1) Mr Paulo has to have 64 maple sugar trees to make 16 gallons of maple syrup
 * 2) 100:25
 * 4:1
 * 64:18
 * 1) 18 x 4=64
 * 2) It takes 4 maple trees to make 1 gallon of maple syrup
 * B) //A 5 minute shower requires about 18 gallons of water. About how much water do you use for an 8 minute shower? How much water will you use if you take an 8 minute shower every day of the year?//**
 * 1) An 8 minute shower everyday in a year would take up 10,512 gallons a year
 * 5:18
 * 5:3
 * 8:18
 * 1) 5 x 8 = 28.8 gallons
 * 2) 28.8 gallons of water each day in a year would equal to 10,512 gallons a year


 * C) //A double spaced page of text contains about 250 words if it is printed in Times with a font size of 12, and about 330 words if it is printed in Times with the font size of 10. Jeremy printed his term paper in the computer lab. He used 10 - point Times and the paper came to 15 double spaced pages. Jeremy's teacher requires term papers be 20 double spaced pages long. If Jeremy changes the font to the 12 - point Times, how long will his paper be?//**
 * 1) If a 12 point size font would equal up to 18 pages
 * 10:15
 * 2:3
 * 12:18
 * 1) 18 would be the amount of pages printed when it would use 12 point font


 * D) //Jogging burns 100 per mile. Elizabeth jogs at a rate of 4.5 miles per hour. How long will it take her to burn 1200 - calorie lunch she ate at Burger Heaven?//**
 * 1) Elizabeth would have to run for 2 hours and 45 minutes to burn 1200 calories
 * 1:4.5
 * 1) 2.65:12
 * 2) 4.5 x 2.65
 * 3) 1200 calories: 12 miles
 * 12:2.75
 * 1) To burn 1200 calories Elizabeth has to run 12 miles at a rate of 4.5 miles per hour


 * 6.2 Follow Up**
 * //Ask adults you know if they use rules of thumb in their jobs or at home. Write down one of the rules you learn. Write a problem that can be solved using the rule.//**