x 3 x + 3 = 8 Come play with numbers!
Expressions

Can we snap maths into Lego bricks?

# Terms and coefficients An **expression** is a maths phrase with no “is equal to” yet: `4x + 7 − y` Split it into **terms** at + and − (keep the sign with the term): - `+4x` - `+7` - `−y` The **coefficient** is the number glued to the letter: - In `4x`, coefficient is **4** - In `−y`, coefficient is **−1** (invisible 1) - In `x`, coefficient is **1** > Terms are like Lego bricks. Later we only snap **matching** bricks together. ## Terms are the bricks Take `4x + 7 − y`. Walk from left to right. Every time you hit + or − (that is not inside a later bracket), you start a new brick. Carry the sign: 1. `+4x` 2. `+7` 3. `−y` ### Coefficient checklist Ask: “What number is multiplying this letter?” - `6n` → 6 - `n` → 1 - `−n` → −1 - `−6n` → −6 ### Why teachers care If you cannot see terms, you cannot collect like terms, and you cannot expand brackets cleanly. This lesson is the hinge.

By the end of this lesson

Split an expression into terms, and name the coefficient of each letter-term (including the invisible 1 and −1).

Remember

  • An expression has no “=” yet. An equation does.
  • Split terms at + and −, and keep the sign with the term.
  • In 4x the coefficient is 4. In x it is 1. In −y it is −1.
  • 4x + 7 − y has three terms: +4x, +7, −y.
  • Terms are Lego bricks. Later we only snap matching bricks.

Worked examples

Cover the answer. Try the steps on paper, then open them.

Example 1 — Split 6a − 2 + b

List every term with its sign.

  1. +6a
  2. −2
  3. +b

Answer: +6a, −2, +b

Check: Three terms.

Example 2 — Invisible coefficients

Name the coefficient of n in n, of m in −m, of k in 5k.

  1. n → 1
  2. −m → −1
  3. 5k → 5

Answer: 1, −1, 5

Check: Write the 1 until you never forget it.

Example 3 — Expression or equation?

Sort: 2x + 1 and 2x + 1 = 9

  1. 2x + 1 is an expression (a phrase)
  2. 2x + 1 = 9 is an equation (a full sentence with =)

Answer: expression ; equation

Check: = is the difference.

Common mistakes

Slip Counting 4x + 7 as one term because it is “one thing”.

Fix Two terms: 4x and 7.

Split at the +.

Slip Saying the coefficient of −y is 1 or y.

Fix It is −1.

The minus is part of the coefficient.

Slip Calling 4x + 7 an equation.

Fix No equals sign → expression.

Save the word equation for =.

Try on paper first

Write the answer, then tap Reveal. These are not the quiz — they are warm-ups.

1. How many terms in 3x + 2y − 5?

Answer: 3

2. Coefficient of y in 3x + 2y − 5?

Answer: 2

3. Coefficient of x in −x + 9?

Answer: −1

4. Is 5n − 1 an equation? Yes or no.

Answer: No

Touch practice

8 tap / type

Tap an option or type the answer. Retry any miss. Extra generated questions appear after the set if this topic allows it.

Optional picture lab

After practice

Real world

A bill is items + tax — separate terms.

Connect

Expressions in code are built from pieces too.

⭐ Star quiz

9 questions

Finish the touch practice first if you can. Then answer without peeking. Read every “why”.

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