Number Sentences and Equations
Number sentences use symbols like +, −, ×, ÷, and = to express mathematical relationships, and unknown values can be found by thinking about what makes both sides equal.
What You Need to Know
Key Concept Diagram
A number sentence uses numbers and operation symbols to show a mathematical relationship (e.g. 4 + 3 = 7)
An equation has an equals sign showing two expressions with the same value
An unknown (represented by a box, ?, or letter) is a missing value to find
Inverse operations (opposite operations) help solve for unknowns: addition ↔ subtraction, multiplication ↔ division
Key Vocabulary
Number sentence
A mathematical statement using numbers and symbols such as +, −, ×, ÷, =
Equation
A number sentence with an equals sign, showing two expressions are equal
Unknown
A missing value in a number sentence, often shown as a box, question mark, or letter
Inverse operation
The opposite operation used to undo another (e.g. subtraction undoes addition)
Knowledge Check
Select the correct answer for each question. Click "Check Answer" to see if you are right.
Question 1
What value makes this number sentence true? □ × 6 = 42
Question 2
Which number sentence is an equation?
Question 3
Solve: 56 ÷ □ = 8
Key Concepts Summary
- ●A number sentence uses numbers and operation symbols to show a mathematical relationship (e.g. 4 + 3 = 7)
- ●An equation has an equals sign showing two expressions with the same value
- ●An unknown (represented by a box, ?, or letter) is a missing value to find
- ●Inverse operations (opposite operations) help solve for unknowns: addition ↔ subtraction, multiplication ↔ division