advertisement

Order of Operation Common Mistakes Order of Operation – PEMDAS Parenthesis Exponents Multiply and Divide In the order you see it from left to right! Add and Subtract PEMDAS – Parenthesis Common Mistakes How to work: Parenthesis Add/Subtract, apply exponent rules, multiply/divide inside the parenthesis first. Step 1: Multiply 6 and 2 Step 2: Subtract -4 and 12 Step 3: Multiply 3 and 8 Ex. 3(−4 + 6 ⋅ 2) = 3(−4 + 12) = 3(8) = 24 Complete Manual: ..\Order of Operation Review.docx To view; right click and open the hyperlink Common Mistakes Distributing before simplifying inside the parenthesis. 3(−4 + 6 ⋅ 2) Incorrect: = −12 + 18 ⋅ 6 = −12 + 108 = 96 Incorrectly working the inside of the parenthesis. In this case the student subtracted the -4 and 6 first instead of multiplying the 6 and 2 first. Incorrect: 3(−4 + 6 ⋅ 2) = 3(2 ⋅ 2) = 3(4) = 12 PEMDAS – Exponents How to work Exponents n Definition: ax a Is the coefficient x n Is the variable Multiplying the exponent by the coefficient. 2 Incorrect: 4 = 4 ⋅ 2 = 8 Is the exponent The exponent represents the number of times you multiply the number by itself. Common Mistakes Ex. 33 = 3 ⋅ 3 ⋅ 3 = 27 Correct: 4 = 4 ⋅ 4 = 16 Applying the exponent rule incorrectly with negative numbers. Incorrect: − 32 = −3 ⋅ −3 = 9 − 6 2 = −6 ⋅ −6 = 36 4 2 = 4 ⋅ 4 = 16 (−5) 2 = −5 ⋅ −5 = 25 − 82 = −1(8 ⋅ 8) = −64 2 Correct: − 32 = −1(3 ⋅ 3) = −9 − 6 2 = −1(6 ⋅ 6) = −36 (−6) 2 = −6 ⋅ −6 = 36 Remember: In order to square a negative number, the number MUST be inside the parenthesis. Complete Manual: ..\Order of Operation Review.docx To view; right click and open the hyperlink PEMDAS – Multiplying and Dividing How to Multiply and Divide Multiply and divide in the order that you see it left to right. Ex. Common Mistakes Always multiplying first. Incorrect: 16 ÷ 8 ⋅ 2 = 16 ÷ 16 = 1 − 8 ⋅ 2 ÷ 4 = −16 ÷ 4 = −4 − 12 ÷ 4 ⋅ 4 = −12 ÷ 16 = 12 3 = 16 4 30 ÷ 6 ⋅ 5 = 5 ⋅ 5 = 25 16 ÷ 8 ⋅ 2 = 2 ⋅ 2 = 4 Correct: 16 ÷ 8 ⋅ 2 = 2 ⋅ 2 = 4 − 12 ÷ 4 ⋅ 4 = −3 ⋅ 4 = −12 Complete Manual:..\Order of Operation Review.docx To view; right click and open the hyperlink PEMDAS – Adding and Subtracting How to add and subtract Add and subtract real numbers in any order. Helpful hint: Add up all the positive numbers Add up all the negative numbers Subtract once Ex. − 5 + 20 − 8 + 2 = −13 + 22 =9 Complete Manual: ..\Order of Operation Review.docx To view; right click and open the hyperlink Common Mistakes Adding and subtracting incorrectly. Incorrect: − 15 + 6 =9 Correct: − 15 + 6 = −9