Two-Step Reasoning with Unknowns (Grades 6–7)
This pulls the pieces together: set up an equation from a situation, then solve it in two steps. Real problems often hide an equation — "I think of a number, multiply by 2 and add 7 to get 15." Writing that as 2n + 7 = 15 and solving (undo +7, then ÷2) gives n = 4. The skill is turning words into an equation, then using inverse operations to solve.
Understanding two-step reasoning with unknowns
This pulls the pieces together: set up an equation from a situation, then solve it in two steps. Real problems often hide an equation — "I think of a number, multiply by 2 and add 7 to get 15." Writing that as 2n + 7 = 15 and solving (undo +7, then ÷2) gives n = 4. The skill is turning words into an equation, then using inverse operations to solve.
Key Idea
This pulls the pieces together: set up an equation from a situation, then solve it in two steps. Real problems often hide an equation — "I think of a number, multiply by 2 and add 7 to get 15." Writing that as 2n + 7 = 15 and solving (undo +7, then ÷2) gives n = 4. The skill is turning words into an equation, then using inverse operations to solve.
Seeing it in action
Worked example
"Twice a number plus 7 is 15." Find the number.
Write it: 2n + 7 = 15.
Solve: 2n = 15 − 7 = 8, so n = 8 ÷ 2 = 4. (Check: 2·4 + 7 = 15 ✓.)
Translate the words, then solve backward.
Try a few
"3 times a number minus 1 is 14."
"A number divided by 2, plus 4, is 9."
"5 more than 4 times a number is 25."
Function Foundry
A calm pre-algebra game for function machines, inverse operations, and solving for an unknown.
Ready for the interactive lab?
Practice two-step reasoning with unknowns in Numeris with instant feedback.
Master it in the workbook.
The Pre-Algebra workbook is currently in editorial review.
Coming SoonWant a printable set too?
Get the free Reasonwell sample pack while the math workbook line is coming soon.