Mathwords logoMathwords

Arithmetic

Arithmetic

Calculations involving numbers. This typically involves the basic operations addition, subtraction, multiplication, division, and exponents. Some people also consider roots, logarithms, calculations modulo n, and other more sophisticated operations to be arithmetic as well.

 

 

See also

Modular arithmetic, algebra

Worked Example

Problem: Evaluate the arithmetic expression: 8 + 3 × (10 − 4) ÷ 2
Step 1: Apply the order of operations. Start with the parentheses: compute 10 − 4.
104=610 - 4 = 6
Step 2: Next, handle multiplication and division from left to right. Multiply 3 × 6.
3×6=183 \times 6 = 18
Step 3: Then divide 18 ÷ 2.
18÷2=918 \div 2 = 9
Step 4: Finally, perform the addition.
8+9=178 + 9 = 17
Answer: The value of the expression is 17.

Another Example

Problem: A store sells notebooks for 4eachandpensfor4 each and pens for2 each. You buy 5 notebooks and 8 pens. What is the total cost?
Step 1: Use multiplication to find the cost of the notebooks.
5×4=205 \times 4 = 20
Step 2: Use multiplication to find the cost of the pens.
8×2=168 \times 2 = 16
Step 3: Use addition to find the total cost.
20+16=3620 + 16 = 36
Answer: The total cost is $36.

Frequently Asked Questions

What is the difference between arithmetic and mathematics?
Arithmetic is a branch of mathematics focused specifically on numbers and basic operations like addition, subtraction, multiplication, and division. Mathematics is much broader and includes fields like geometry, algebra, calculus, statistics, and many others. Think of arithmetic as the foundation that the rest of mathematics builds upon.
What are the four basic arithmetic operations?
The four basic arithmetic operations are addition (+), subtraction (−), multiplication (×), and division (÷). Exponentiation is often considered a fifth fundamental operation. Together, these operations form the core tools you use to work with numbers.

Arithmetic vs. Algebra

Arithmetic works with known numbers and computes definite results (e.g., 3 + 5 = 8). Algebra introduces variables to represent unknown or general quantities and focuses on finding their values or expressing relationships (e.g., x + 5 = 8, so x = 3). Algebra relies on arithmetic at every step, but it extends the reasoning to situations where not all values are given.

Why It Matters

Arithmetic is the most fundamental skill in all of mathematics. Every calculation you encounter—whether splitting a restaurant bill, measuring ingredients for a recipe, or computing interest on a savings account—depends on arithmetic. Mastering it is essential before moving into algebra, geometry, or any other mathematical discipline.

Common Mistakes

Mistake: Ignoring the order of operations and performing calculations strictly from left to right.
Correction: Always follow the standard order: parentheses first, then exponents, then multiplication and division (left to right), and finally addition and subtraction (left to right). For example, 2 + 3 × 4 equals 14, not 20.
Mistake: Treating subtraction and division as commutative (thinking order doesn't matter).
Correction: Addition and multiplication are commutative (a + b = b + a), but subtraction and division are not. For instance, 7 − 3 = 4 while 3 − 7 = −4, and 12 ÷ 3 = 4 while 3 ÷ 12 = 0.25.

Related Terms

  • AlgebraExtends arithmetic by introducing variables and equations
  • Root of a NumberAn extended arithmetic operation inverting exponentiation
  • LogarithmAn advanced operation related to exponents
  • Modulo nArithmetic operation giving the remainder after division
  • Modular ArithmeticSystem of arithmetic with wrap-around at a modulus
  • Order of OperationsRules governing the sequence of arithmetic steps
  • IntegersThe primary number set used in basic arithmetic