Order of Operations
Apply the order of operations (PEMDAS) in Grade 10 algebra to evaluate multi-step expressions correctly: parentheses, exponents, multiplication/division left-to-right, then addition/subtraction.
Key Concepts
1. Parentheses and grouping symbols 2. Exponents 3. Multiply and divide from left to right 4. Add and subtract from left to right.
Simplify $20 4 \cdot (7 5)^2 \div 8$. Solution: $20 4 \cdot (2)^2 \div 8 = 20 4 \cdot 4 \div 8 = 20 16 \div 8 = 20 2 = 18$. Evaluate $x(y z) + z^3$ for $x=5, y=4, z=2$. Solution: $5(4 2) + 2^3 = 5(2) + 8 = 10 + 8 = 18$.
Remember the powerful phrase 'Please Excuse My Dear Aunt Sally'! It's the ultimate guide for navigating complex math problems. First, handle anything in Parentheses. Next, conquer all the Exponents. Then, team up Multiplication and Division (working left to right). Finally, finish with Addition and Subtraction (also left to right). This order ensures everyone gets the same correct answer.
Common Questions
What does PEMDAS stand for and what order does it prescribe?
Parentheses, Exponents, Multiplication/Division (left to right), Addition/Subtraction (left to right). Evaluate innermost parentheses first, then work outward and left to right for equal-precedence operations.
Evaluate 3+4×2²-1 using order of operations.
Exponents first: 4×4=16. Multiplication: 16. Addition/Subtraction left to right: 3+16-1=18.
What is the value of 18÷3×2?
Division and multiplication have equal precedence, so evaluate left to right: 18÷3=6, then 6×2=12. Never multiply before dividing just because multiplication appears in the acronym first.