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INTRODUCTION TO GEOGEBRA
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In order to play with these interactive GeoGebra modules you will need to make sure that you have the Java Plugin installed. If you don't have the plugin installed you will not see the interactive module below. If you don't see the interactive module below download the Java Plugin here. Once the Java plugin is installed restart your browser and come back to this page and will see the GeoGebra module below.
PLEASE READ THE FOLLOWING:
To see some of the features that you can control in a GeoGebra module see my video here. Even though the video deals with the toolkit functions there is plenty to learn about how to interact with any GeoGebra module.
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EVALUATING AN ALGEBRAIC EXPRESSION USING PEMDAS
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IMPORTANT: This set of exercises assumes that you can multiply, divide, add, subtract and use exponents with integers.
Arithmetic Expressiondefintion: an set of symbols made up of numbers, operations, exponents and parentheses.
Evaluatedefintion: a command to get a numerical answer to an arithmetic expression.
PEMDAS is an acronym that represents the order in which an arithmetic expression is to be evaluated. When evaluating an arithmetic expression you evaluate parentheses first, exponents second, multiplication third, division fourth, addition fifth and finally subtraction. If you have multiple operations of the same type you are to work from left to right until you complete all the operations of the same type.
EXAMPLES OF EVALUATING AN ARITHMETIC EXPRESSION - EXERCISE 3
ex. 1) Evaluate 3 + 2
ans:
3 + 2
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ex. 2) Evaluate 3 + 2(4 - 7)
ans:
3 + 2(4 - 7)
3 + 2(-3)
3 + -6
-3
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ex. 3) Evaluate 32 + 2(4 - 7)
ans:
32 + 2(4 - 7
9 + 2(4 - 7)
9 + 2(-3)
9 + -6
3
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ex. 4) Evaluate
32(-9 - 4) + 2(4 - 7)
ans:
32(-9 - 4) + 2(4 - 7)
32(-13) + 2(4 - 7)
32(-13) + 2(-3)
9(-13) + 2(-3)
-117 + 2(-3)
-117 + -6
-123
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ex. 5) Evaluate
32(-9 - 4) + 2(42 - 7)
ans:
3 2(-9 - 4) + 2(42 - 7)
3 2(-13) + 2(42 - 7)
3 2(-13) + 2(16 - 7)
32(-13) + 2(9)
9(-13) + 2(9)
-117 + 2(9)
-117 + 18
-99
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ex. 6) Evaluate
32(-9 - 14/7) + 2(4/2 - 7)2
ans:
3 2(-9 - 14/7) + 2(4/2 - 7)2
3 2(-9 - 2) + 2(4/2 - 7)2
3 2(-11) + 2(4/2 - 7)2
3 2(-11) + 2(2 - 7)2
3 2(-11) + 2(-5)2
9(-11) + 2(-5)2
9 (-11) + 2(25)
-99 + 2(25)
-99 + 50
-49
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Variabledefintion: in the game of mathematics it is a letter of the alphabet that can be replaced by a number.
Algebraic Expressiondefintion: an set of symbols made up of numbers, operations, exponents, parentheses and variable(s).
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HOW TO USE THIS MODULE
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Step 1) On the first line of your paper, write down the algebraic expression abc + d(e + f) on a piece of paper
Step 2) Choose values for the variables by moving the sliders for a, b, c, d, e and f.
Step 3) On the second line of your paper, write down the values of those variables on your paper.
Step 4) On the third line of your paper substitute the numbers into the variables
of your algebraic expression
Step 5)
On the next line of your paper, start evaluating the mathematical expression using PEMDAS. ONLY DO ONE STEP AT A TIME!
Step 6) After each step click your mouse in the "check box" to reveal whether you did the process correctly.
Step 7) If you make an error and cannot understand WHY you have an error ask you teacher WHY you did PEMDAS improperly.
Step 8) Once you finish, click the reset button,  , and the module will be set to the original state. Now you can choose new numbers for your variables.
Comment: Make sure you number each problem that you do. The first problem that you do is to be labeled 1, the next problem 2, so on and so forth.
MODULE BELOW:
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