Overview
This lecture covers how to solve math problems involving two or more operations (addition, subtraction, multiplication, division) following the correct order of operations, without exponents or grouping symbols.
Order of Operations (MDAS Rule)
- MDAS stands for Multiplication, Division, Addition, and Subtraction.
- Perform multiplication and division first, from left to right.
- After multiplication and division, do addition and subtraction from left to right.
Example Problems
Example 1: 20 - 4 + 6 × 3
- First, compute 6 × 3 = 18.
- Then, 20 - 4 = 16.
- Add the results: 16 + 18 = 34 (Note: Transcript might have calculation errors, but notes reflect logical MDAS).
Example 2: 37 + 3 × 2 ÷ 6
- Multiply: 3 × 2 = 6.
- Divide: 6 ÷ 6 = 1.
- Add: 37 + 1 = 38.
Example 3: 14 ÷ 2 - 4 + 3 × 2
- Divide: 14 ÷ 2 = 7.
- Multiply: 3 × 2 = 6.
- Subtract: 7 - 4 = 3.
- Add: 3 + 6 = 9.
Example 4: 63 ÷ 7 + 5 × 2 - 6
- Divide: 63 ÷ 7 = 9.
- Multiply: 5 × 2 = 10.
- Add: 9 + 10 = 19.
- Subtract: 19 - 6 = 13.
Key Terms & Definitions
- MDAS — Order of operations: Multiplication, Division, Addition, Subtraction.
- Operation — Mathematical process such as addition (+), subtraction (−), multiplication (×), or division (÷).
Action Items / Next Steps
- Practice more problems using the MDAS rule.
- Review homework problems that involve multiple operations without exponents or grouping symbols.