Numerical Expressions
Числовые выражения
What is a Numerical Expression?
Что такое числовое выражение?
Definition: A numerical expression is a mathematical phrase that combines numbers and operation symbols (\(+\), \(−\), \(×\), \(÷\), and exponents) to represent a specific calculation. It may also include parentheses to indicate grouping.
Components of Numerical Expressions:
- Numbers 3, 5, 7, 15, 0.8, etc.
- Operations + − × ÷
- Powers ², ³, etc.
- Parentheses ( )
Examples:
3 + 5 × 2
(7 − 3)²
15 ÷ 3 + 8
Value of an Expression
Значение выражения
Definition: The value of an expression is the result obtained after performing all operations. Each numerical expression has exactly one value.
| Expression | Calculation | Value |
|---|---|---|
3 + 5 × 2 |
3 + 10 | 13 |
(7 − 3)² |
4² = 4 × 4 | 16 |
15 ÷ 3 + 8 |
5 + 8 | 13 |
Order of Operations
The Rules (PEMDAS/BODMAS)
1st: Parentheses — Solve inside ( ) first
2nd: Powers — Calculate exponents
3rd: × and ÷ — Left to right
4th: + and − — Left to right
Interactive visualization — available in the full lesson