NUMBER · GRADE 6 · ALBERTAOUTCOME AB-MAT6-A1
L3 · Like terms
Learning goal
“I can simplify an expression by combining like terms - adding or subtracting the coefficients of terms with the same variable - while constants stay separate.”
Variable — a letter that stands for a number, like x or n.
Term — one piece of an expression, separated by + or -: in 5x + 3, the terms are 5x and 3.
Coefficient — the number multiplied by a variable in a term: in 5x, the coefficient is 5.
Like terms — terms with exactly the same variable (or no variable at all): 3x and 2x are like terms; 3x and 3 are NOT.
Worked example
Simplify 3x + 2x. Step 1: Read it with arrows: 3 arrows of length x, then 2 more arrows of length x, end to end. Step 2: Count the arrows: 5 arrows of length x in total. Step 3: 3x + 2x = 5x. The coefficients add (3 + 2); the variable does not change. Combining like terms is counting - x stays x, and we never write x^2 here, because nothing was multiplied.
Check yourself — explain it
3x + 2x = 5x because...
Paired problem — example still visible
Simplify 9b - 4b -> 5b (9 arrows of b, remove 4: 5 left)
Faded completion — last step is yours
"6n + ___n = 11n" -> 5
Ready to practise?
10 scored questions with a 3-rung hint ladder. Mastery needs 8/10 plus both gate questions.