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No More Algebra— NEED MORE ANSWERS FOR NEXT TIME I TEACH THIS How to Conquer the Algebra problems…without Algebra.
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Dealing with Word Problems 1. Know the question. -Read the whole problem and underline the actual question. 2. Let the answers help. -Look for clues on how to solve and ways to use POE. 3. Break the problem into bite-sized pieces.
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Don’t forget… What we often forget is that x is substituting for some real value. Equations use x because that value is unknown. That leads us to our first strategy…
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Strategy 1: PLUGGING IN If you had $1 and you bought 2 pieces of candy at 25 cents apiece, how much change would you have? 50 cents, of course. If you had d dollars and bought p pieces of candy at c cents apiece, how much change would you have? Umm…letter of day?
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PLUGGING IN…continued Numbers are a lot easier to work with than variables. Therefore, when you see variables on the ACT, you can usually make things a lot easier on yourself by using numbers instead.
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Use Plugging In: when there are variables in the answer choices. when solving word problems or plug- and-chug questions. for questions of any difficulty level.
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What to Do When You Plug In 1. Identify the opportunity. Can you plug in on this question? 2. Choose a good number. Make the math easy on yourself. 3. Find a target answer. Answer the question posed in the problem with your number, and circle your target answer. 4. Test all the answer choices. If two of them work, try a new number.
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Let’s Try it… 21. John has x red pencils, and three times as many red pencils as blue pencils. If he has four more yellow pencils than blue pencils, then in terms of x, how many yellow pencils does John have?
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21. John has x red pencils, and three times as many red pencils as blue pencils. If he has four more yellow pencils than blue pencils, then in terms of x how many yellow pencils does John have? 1.) Underline the question.
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21. John has x red pencils, and three times as many red pencils as blue pencils. If he has four more yellow pencils than blue pencils, then in terms of x how many yellow pencils does John have? 1.) Underline the question.
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21. John has x red pencils, and three times as many red pencils as blue pencils. If he has four more yellow pencils than blue pencils, then in terms of x how many yellow pencils does John have? 1.) Underline the question. 2.) Let the answers help. -The answers help a lot here: each contains the variable x, which means we can plug in.
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21. John has x red pencils, and three times as many red pencils as blue pencils. If he has four more yellow pencils than blue pencils, then in terms of x how many yellow pencils does John have? 1.) Underline the question. 2.) Let the answers help. -The answers help a lot here: each contains the variable x, which means we can plug in. 3.) Break the problem into bite-sized pieces. -To make it easy, let’s make x = 3, so John has 3 red pencils.
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So, let’s find our target answer. 21. John has x red pencils, and three times as many red pencils as blue pencils. If he has four more yellow pencils than blue pencils, then in terms of x how many yellow pencils does John have? Since x = 3, John has 3 red pencils. He has 3 times as many red pencils as blue pencils; therefore he must have 1 blue pencil. He has 4 more yellow pencils than blue pencils, so he must have 5 yellow pencils. So 5 is our target answer.
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Remember, x = 3; Target answer is 5.
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Let’s Try Some More Examples
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How to Crack It Let’s pick an easy number like x = 2. So our target value will be…
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Remember, x = 2; Target Answer is 8.
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One More “Plug In” Example… Try…
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How to Crack It Using the first equation, let’s choose x=8 and z=2. Using these values, let’s find the value for y.
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Strategy 2: PITA What happens if there are no variables in the equation? Do we have to go back to algebra? NO! Another strategy is to use PITA. PITA = Plugging In The Answers
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Use PITA when: answer choices are numbers in ascending or descending order the question asks for a specific amount. Questions will usually be “what?” or “how many?” you get the urge to do algebra even when there are no variables in the problem.
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Pointers in using the PITA strategy: Start with choice C or H to help with POE. When you find the correct answer, STOP!
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Let’s Try Using PITA… 2.If $600 were deposited in a bank account for one year and earned interest of $42, what was the interest rate? F. 6.26% G. 7.00% H. 8.00% J. 9.00% K. 9.50%
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2. If $600 were deposited in a bank account for one year and earned interest of $42, what was the interest rate? F. 6.26% G. 7.00% H. 8.00% J. 9.00% K. 9.50% Let’s start with the middle choice. That way if it is too high or too low, we’ll be able to use POE more efficiently. 8%=8/100, so $600 8/100=$48 This answer is too high so we can also eliminate J and K. $600 7/100=$42 YES! Since we haven’t introduced any of our own numbers into this problem, we can STOP once we find the right answer. The correct answer is G.
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One More… 49.In a piggy bank, there are pennies, nickels, dimes, and quarters that total $2.17 in value. If there are 3 times as many pennies as there are dimes, 1 more dime than nickels, and 2 more quarters than dimes, then how many pennies are in the piggy bank? A. 12 B. 15 C. 18 D. 21 E. 24
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In a piggy bank, there are pennies, nickels, dimes, and quarters that total $2.17 in value. If there are 3 times as many pennies as there are dimes, 1 more dime than nickels, and 2 more quarters than dimes, then how many pennies are in the piggy bank? A. 12 B. 15 C. 18 D. 21 E. 24 Let’s begin with 18. 18 pennies So that would mean 6 dimes, 5 nickels, and 8 quarters. 18 P (0.18) + 6 D (.60) + 5 N (.25) + 8 Q (2.00) = $3.03 So C is wrong, which means so are D and E. Keep going until you come up with the right answer. What did you get?
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Your Turn… Now try the Algebra Drill problems.
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