Numbers are the building blocks of mathematics, but they become truly useful when we combine them using operations such as addition, subtraction, multiplication, division, powers, and grouping symbols. These combinations are called numeric expressions, and learning how to read and simplify them is one of the most important skills in math.
TLDR: A numeric expression is a mathematical phrase made only of numbers and operation symbols, with no variables. To solve one correctly, follow the order of operations: parentheses, exponents, multiplication and division, then addition and subtraction. Numeric expressions appear everywhere, from calculating shopping totals to measuring distance, time, and money. The examples below show how to simplify them step by step.
What Is a Numeric Expression?
A numeric expression is a combination of numbers and mathematical operations. Unlike an equation, it does not contain an equals sign showing two sides are the same. Unlike an algebraic expression, it does not contain letters or variables.
For example:
- 8 + 5 is a numeric expression.
- 12 ÷ 3 × 4 is a numeric expression.
- 6 + x is not a numeric expression because it contains a variable.
- 9 + 2 = 11 is an equation, not just an expression.
The goal when working with a numeric expression is usually to simplify it, meaning to calculate its value.
The Order of Operations
Numeric expressions can become confusing if we do the operations in the wrong order. For example, consider 4 + 3 × 2. If you add first, you get 14. If you multiply first, you get 10. Only one answer is correct according to standard math rules.
To avoid confusion, mathematicians use the order of operations. A common memory aid is PEMDAS:
- Parentheses
- Exponents
- Multiplication and Division, from left to right
- Addition and Subtraction, from left to right
It is important to remember that multiplication and division have the same priority. You solve them in the order they appear from left to right. The same rule applies to addition and subtraction.
Example 1: A Simple Expression
Let’s simplify:
7 + 6 × 2
Many beginners want to add 7 + 6 first, but multiplication comes before addition.
- Multiply first: 6 × 2 = 12
- Add: 7 + 12 = 19
Answer: 19
This example shows why the order of operations matters. The expression is not solved from left to right when multiplication is involved before addition.
Example 2: Using Parentheses
Now compare the previous expression with this one:
(7 + 6) × 2
Parentheses tell us what to do first.
- Solve inside the parentheses: 7 + 6 = 13
- Multiply: 13 × 2 = 26
Answer: 26
Notice how 7 + 6 × 2 equals 19, while (7 + 6) × 2 equals 26. The same numbers appear in both expressions, but the grouping changes the value.
Example 3: Division and Multiplication from Left to Right
Simplify:
24 ÷ 3 × 2
Since division and multiplication have equal priority, solve from left to right.
- 24 ÷ 3 = 8
- 8 × 2 = 16
Answer: 16
A common mistake is to multiply 3 × 2 first, but that would ignore the left-to-right rule. Unless parentheses say otherwise, work across the expression in order for operations with equal priority.
Example 4: Expressions with Exponents
Exponents show repeated multiplication. For example, 32 means 3 × 3, which equals 9.
Simplify:
5 + 23 × 4
- Evaluate the exponent: 23 = 8
- Multiply: 8 × 4 = 32
- Add: 5 + 32 = 37
Answer: 37
Exponents are solved before multiplication, division, addition, or subtraction, unless they are inside parentheses that must be handled first.
Example 5: A Longer Numeric Expression
Let’s try a more detailed problem:
18 − 2 × (4 + 3) + 62 ÷ 9
This expression includes parentheses, multiplication, an exponent, division, subtraction, and addition. We handle it one step at a time.
- Parentheses first: 4 + 3 = 7
- Rewrite: 18 − 2 × 7 + 62 ÷ 9
- Exponent: 62 = 36
- Rewrite: 18 − 2 × 7 + 36 ÷ 9
- Multiplication and division from left to right: 2 × 7 = 14 and 36 ÷ 9 = 4
- Rewrite: 18 − 14 + 4
- Add and subtract from left to right: 18 − 14 = 4, then 4 + 4 = 8
Answer: 8
This type of expression may look intimidating at first, but breaking it into smaller steps makes it manageable.
Real-Life Uses of Numeric Expressions
Numeric expressions are not limited to textbooks. They appear often in everyday situations. When you calculate the total cost of several items, estimate travel time, compare discounts, or divide a restaurant bill, you are using numeric expressions.
For example, suppose you buy 3 notebooks for $4 each and a pen for $2. The total cost can be written as:
3 × 4 + 2
- Multiply: 3 × 4 = 12
- Add: 12 + 2 = 14
Total cost: $14
If the store gives you a $3 discount, the expression becomes:
3 × 4 + 2 − 3
The value is 11, so you pay $11.
Common Mistakes to Avoid
When simplifying numeric expressions, students often make small errors that change the final answer. Watch out for these:
- Ignoring parentheses: Always solve grouped operations first.
- Adding before multiplying: Multiplication usually comes before addition.
- Forgetting left-to-right order: Multiplication and division are solved in the order they appear.
- Misreading exponents: 42 means 4 × 4, not 4 × 2.
- Skipping steps: Writing each step helps prevent confusion.
Tips for Solving Numeric Expressions
Here are a few simple strategies that make numeric expressions easier:
- Underline or circle parentheses so you remember to solve them first.
- Rewrite the expression after each step to keep your work organized.
- Handle one operation at a time instead of doing too much mentally.
- Check your answer by reviewing the order of operations.
Numeric expressions may seem like simple math phrases, but they teach a powerful habit: solving problems logically and in the correct order. Once you understand how operations work together, longer expressions become less mysterious. With practice, you can look at a complex expression, break it into clear steps, and confidently find its value.
