lesson 4

# Order of Operations

• When evaluating mathematical expressions we follow this order of operations:
1. Parentheses (from the inside out)
2. Exponents (from right to left)
3. Multiplication and division (from left to right)
4. Addition and subtraction (from left to right)

Example:

Evaluate the expression: \eqalign{ & {{2 \times {3^3} \times {4^2} – 31} \over {4\left[ {5 – \left( {3 – 7} \right) \times 6} \right] + 3}} \cr & = {{2 \times {3^3} \times {4^2} – 31} \over {4\left[ {5 – \left( { – 4} \right) \times 6} \right] + 3}} \cr & = {{2 \times {3^3} \times {4^2} – 31} \over {4\left[ {5 – \left( { – 24} \right)} \right] + 3}} \cr & = {{2 \times {3^3} \times {4^2} – 31} \over {4\left[ {5 + 24} \right] + 3}} \cr & = {{2 \times {3^3} \times {4^2} – 31} \over {4 \times 29 + 3}} \cr & = {{2 \times 27 \times 16 – 31} \over {4 \times 29 + 3}} \cr & = {{864 – 31} \over {116 + 3}} \cr & = {{833} \over {119}} \cr & = 7 \cr}