'Expression' vs 'Equation': What's the Difference?

By Katie Moore, updated on October 23, 2023

‘Expression’ vs ‘Equation’: What’s the difference? The interesting thing about language is that words can have their own meanings in a given context. The words in this article may bring you back to a high school calculus class, but let’s dive into all the meanings and comparisons between ‘Expression’ vs ‘Equation’.

In a hurry? Here’s a short version of what’s to come:

• ‘Expression’ in mathematics is a finite combination of numbers and symbols
• ‘Equation’ in mathematics shows that two expressions are equal, using the = sign

What’s the Difference Between ‘Expression’ vs ‘Equation’?

What makes these two words primarily different in mathematics is that one encompasses the other. Think of Russian nesting dolls where the smaller fits inside the larger. ‘Expressions’ are what make up ‘Equations’ since ‘Equations’ set two or more ‘Expressions’ equal to each other.

• So, it is important to remember that what sets these two apart is the presence of the equal sign (=), and without that symbol, all you have is an ‘Expression.’

In that vein, ‘Expressions’ can be anything from simple combinations of numbers to complex multivariable formulas.

Here are some examples of ‘Expressions’ vs ‘Equations’:

• 3 + 4 is an ‘Expression’
• 12 x 12 = 144 is an ‘Equation’
• 9x+4a/10 is an ‘Expression’
• y = mx + b is an ‘Equation’

At this point, you may be questioning if this is a language or mathematics article. The truth is that these subjects can be intertwined, and in this case, the words ‘Expression’ vs ‘Equation’ can also have more than one definition.

To ensure you’re using the correct meaning of the word in the appropriate scenario, let’s dive into the definitions of our new words individually to learn more. Read below to get a better understanding of ‘Expression’ vs ‘Equation.’

Definition of ‘Expression’: What Does it Mean?

According to Oxford Languages, ‘Expression’ is a noun that means:

• The process of making known one’s thoughts or feelings
• “It was his expression of sympathy.”
• The conveying of feeling in the face or voice, in a work of art, or in the performance of a piece of music
• Their eyes were empty of expression.”
• A look on someone’s face that conveys a certain emotion
• “She wore a  forlorn expression.”
• A word or phrase, especially an idiomatic one, used to convey an idea
• “It’s just an old expression my mom used to say.”
• (mathematics) a collection of symbols that jointly express a quantity
• “The expression for the circumference of a circle is 2πr.”
• The production of something, especially by pressing or squeezing it
• “Essential oils created by distillation and expression.”
• (genetics) the process by which possession of a gene leads to the appearance in the phenotype of the corresponding character
• “The expression of the red hair gene came through.”

Synonyms of ‘Expression’

• Verbalization
• Interpretation
• Remark
• Speech
• Statement
• Aspect
• Character
• Face
• Style
• Term
• Commentary
• Symbols

• Question
• Concealment
• Silence
• Denial
• Suppression
• Blank face
• Grin
• Idiom

Phrases with ‘Expression’

• Idiomatic expression
• Self-expression
• Gene expression
• Mathematical expression
• Facial expression
• Artistic expression
• Expression of gratitude

Definition of ‘Equation’: What Does it Mean?

According to Oxford Languages, ‘Equation’ is a noun that means:

• (mathematics) a statement that the values of two mathematical expressions are equal (indicated by the sign =)
• "They solved for 'x' in the equation."
• The process of equating one thing to another
• “The equation of science with objectivity.”
• A situation or problem in which several factors must be taken into account
• “Money also came into the equation.”
• (chemistry) a symbolic representation of the changes that occur in a chemical reaction, expressed in terms of the formulae of molecules or other species involved

Synonyms of ‘Equation’

• Comparison
• Equalization
• Mathematical problem
• Mathematical statement
• Calculation
• Question
• Equivalence

• Difference
• Inequality
• Discrepancy
• Disparity
• Conflict
• Polarity
• Expression
• Disparity
• Unlikeness

Phrases with ‘Equation’

• Mathematical equation
• Maxwell’s equation
• Easy equation
• Complex equation

Pronunciations: How to Pronounce ‘Expression’ vs ‘Equation’

While most of mathematics is computer and paper-based, there is a fair amount of discussion involved as well. To make sure you feel comfortable entering those conversations, let’s make sure you can pronounce these new words and use them aloud correctly.

Use this phonetic spelling of ‘Expression’ as a guide:

• ‘Eks-preh-shun’ (both of the ‘e’ sounds are flat like in “egg,” and note that the ‘ssio’ makes the “sh” sound)

Use this phonetic spelling of ‘Equation’ as a guide:

• ‘Ee-kway-shun’ (the ‘e’ in this case is wide as in “tee” and see how the ‘tio’ also makes the “sh” sound)

How to Use ‘Expression’ vs ‘Equation’ in a Sentence

The final step to mastering new words is feeling comfortable using them in your own scenarios. Given that ‘Expression’ vs ‘Equation’ have many different meanings, be sure to use the sample sentences below to reference the variety of contexts in which these words can appear.

‘Expression’ Example Sentences

• In math class, we learned that basic expressions can be as simple as adding two numbers, but as we moved through the units, we started adding more symbols.
• She couldn’t quite read his expression and wasn’t sure if he liked the gift or hated it.
• He dyed his hair neon green as a form of self-expression and as a way to demonstrate his individuality.
• Many idiomatic expressions don’t translate directly into other languages, so they can be confusing to learn if you aren’t a native speaker.

‘Equation’ Example Sentences

• One of the most famous equations of all time is Albert Einstein’s e=mc^2, which helped us calculate the amount of energy in objects.
• All manner of factors went into planning the elaborate surprise party, but timing was the most important part of the equation
• For math homework, we got sent home a packet that required us to solve over 50 equations in just one night.
• When he saw how well the others were getting along without him, he knew he was out of the equation

‘Expression’ vs ‘Equation’ Example Sentences

• The professor made it clear that unless there was an equal sign written into the problem, they were looking at an expression, not an equation
• She could tell by the puzzled expressions of her classmates that the equations on the test were going to be hard to solve.
• The equation was made up of a series of complex expressions that had been added together.

Final Advice on ‘Expression’ vs ‘Equation’

Learning words in specific contexts can be both helpful and challenging if you know they have a variety of definitions. But, once you explore new vocabulary in all its capacities, you have automatically given yourself access to all sorts of language opportunities.

Need a recap? Here’s a review of what we’ve covered:

• ‘Expression’ is a mathematical term that refers to a combination of numbers and symbols.
• ‘Equation’ is a mathematical term that states when two expressions of values are equal.
• Remember that an equal sign (=) must be present for it to be an ‘Equation.’

Interested in how other subjects can connect to language? Be sure to read other confusing word articles to get a better sense of how language and writing connect us to the world around us. You can learn a lot about all manner of subjects just by expanding your vocabulary knowledge.