Report

Orders of Operation By: Rachel Nguyen Melinda Sinata Kelley Dallas (Also known as… PEMDAS) • Please (parentheses) • Excuse (Exponets) • My Dear (Multiplication/Divide) • Aunt Sally (Add/Subtract) • Most tutees can evaluate a simple expression like 6 + (5 x 4) ÷ 2 but mistakes are often made when it comes to the order of operations. The tutee knows that the parentheses are there for a reason but may be unsure as to what their significance really is. 1. 2. 3. 4. 5. Calculations in parentheses are done first. When you have more than one set of brackets, do the inner brackets first. Exponents (or radicals) must be done next. Multiply and divide in the order the operations occur. Add and subtract in the order the operations occur. Calculations must be done from left to right. • Simplify inside groupings of parentheses, brackets and braces first. Work with the innermost pair, moving outward. • Simplify the exponents. • Do the multiplication and division in order from left to right. • Do the addition and subtraction in order from left to right. (Parentheses) • Innermost, first • Example 1: 6 × (5 + 3) = 30 + 3 = 33 (wrong) 6 × (5 + 3) = 6 × 8 = 48 (true) (exponents) • Powers or roots • Before Multiply, Divide, Add or Subtract. • Example 2: 5 × 22 = 102 = 100 (wrong) 5 × 22 = 5 × 4 = 20 (true) (Multiplication Or Divide) • From left to right • Multiply or Divide before you Add or Subtract • Example 3: Evaluate 2 + 5 × 3 = 7 × 3 = 21 2 + 5 × 3 = 2 + 15 = 17 (Add or Subtract) • From left to right • Example 4: 30 - 5 + 3 = 30 + 3 = 33 30 - 5 + 3 = 25 + 3 = 28 Evaluate using the order of operations: 150 ÷ (6 + 3 x 8) 2 – 5 150 ÷ (6+24) 2 – 5 150 ÷ (30) 2 – 5 150 ÷ 900 – 5 = 150/900 -5 = 1/6 -5 = 1-30/6 = -29/6 (PEMDAS) (Parentheses, Exponents, Multiply, Divide, Add, Subtract) • Please Excuse My Dear Aunt Sally • Pandas Eat: Mustard on Dumplings, and Apples with Spice. • Please Execute My Deadly Anteater Silently • Pink Elephants Destroy Mice And Snails • Pirates Eat Marshmallows During All Sails