USE OF BRACKETS
Meaning
Brackets are symbols used in mathematics to group numbers or algebraic expressions together. They tell us which operations to do first when solving a problem.
Types of Brackets
- Round brackets ( ) – also called parentheses.
- Square brackets [ ] – used to group expressions within round brackets.
- Curly brackets { } – used for larger grouping when multiple brackets are involved.
Purpose of Brackets
- To indicate the order of operations.
- To clarify which part of the expression should be simplified first.
- To avoid ambiguity in expressions.
Order of Operations
When brackets are present, always solve the expression inside the brackets first, then follow the normal order of operations (BODMAS):
- B – Brackets
- O – Orders (powers, roots)
- D – Division
- M – Multiplication
- A – Addition
- S – Subtraction
Examples
Example 1: Evaluate 5 + (3 + 2)
Step 1: Solve inside the bracket first: 3 + 2 = 5
Step 2: Add the result to 5: 5 + 5 = 10
Example 2: Evaluate (8 − 3) × 2
Step 1: Brackets first: 8 − 3 = 5
Step 2: Multiply: 5 × 2 = 10
Example 3: Evaluate 12 ÷ (2 + 4)
Step 1: Brackets: 2 + 4 = 6
Step 2: Division: 12 ÷ 6 = 2
Example 4: Evaluate 7 + [3 × (4 − 2)]
Step 1: Inner brackets: 4 − 2 = 2
Step 2: Multiply: 3 × 2 = 6
Step 3: Add 7: 7 + 6 = 13
Example 5: Evaluate [8 + (5 − 3)] × 2
Step 1: Inner brackets: 5 − 3 = 2
Step 2: Add: 8 + 2 = 10
Step 3: Multiply by 2: 10 × 2 = 20
Example 6: Evaluate 15 − [2 × (3 + 4)]
Step 1: Inner brackets: 3 + 4 = 7
Step 2: Multiply by 2: 2 × 7 = 14
Step 3: Subtract from 15: 15 − 14 = 1
Important Notes
- Always solve the innermost brackets first if there are multiple layers.
- Brackets do not change the numbers; they only indicate which operations to perform first.
- Use brackets to avoid mistakes in complex calculations.