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Solver Squad Elite Glossary For Grown-Ups Store · opens 13 Nov
Optional · harder

Challenge Lab

Nothing in here is required. Every Mission ends with a Final Unlock, and this is where they all live — with the worked answer, every time.

Bandit Bun, an energetic rabbit mascot in a navy varsity jacket, thinking hard.

Bandit says

“These are the ones I need two tries at. Sometimes three. Nobody is counting.”

This week’s Final Unlock

Week 1 · Foundations. Try it on paper first — the answer is one button away, and looking is not cheating.

The problem

Write an expression for five less than twice a number n, then evaluate it when n = 9.

  1. 2n − 5

    “Twice a number” is 2n. “Five less than” subtracts from it — the order flips, which is the whole trap.

  2. 2(9) − 5 = 18 − 5

    Substitute, then multiply before you subtract.

  3. 13

    Final. Correct.

5 − 2n is the common miss. Read it again: five less than the 2n.

Incorrect answer

How the Lab works

  • Nothing is timed and nothing is scored
  • Every answer is worked, not just marked
  • No account, and no email asked of any student
  • Skipping the Lab costs you nothing in the Missions
The workbook

Solver Society: Codes, Clues & Challenges – Fall 2026 Edition

A full book of the Lab’s kind of problem, printed and sequenced. Lands 13 November.

Store opens 13 Nov

Search keywords: hard algebra 1 problems with answers, algebra challenge problems pdf, algebra puzzles with answers, writing expressions from words practice, five less than twice a number, algebra 1 enrichment, algebra 1 EOC practice, 9th grade algebra challenge, algerbra, algbra, expresions, sunny bun, bandit bun, solver society.

Challenge Lab — the optional hard ones
Skip to main content
Solver Squad Elite Glossary For Grown-Ups Store · opens 13 Nov
Optional · harder

Challenge Lab

Nothing in here is required. Every Mission ends with a Final Unlock, and this is where they all live — with the worked answer, every time.

Bandit Bun, an energetic rabbit mascot in a navy varsity jacket, thinking hard.

Bandit says

“These are the ones I need two tries at. Sometimes three. Nobody is counting.”

This week’s Final Unlock

Week 1 · Foundations. Try it on paper first — the answer is one button away, and looking is not cheating.

The problem

Write an expression for five less than twice a number n, then evaluate it when n = 9.

  1. 2n − 5

    “Twice a number” is 2n. “Five less than” subtracts from it — the order flips, which is the whole trap.

  2. 2(9) − 5 = 18 − 5

    Substitute, then multiply before you subtract.

  3. 13

    Final. Correct.

5 − 2n is the common miss. Read it again: five less than the 2n.

Incorrect answer

What else is in the Lab

How the Lab works

  • Nothing is timed and nothing is scored
  • Every answer is worked, not just marked
  • No account, and no email asked of any student
  • Skipping the Lab costs you nothing in the Missions
The workbook

Solver Society: Codes, Clues & Challenges – Fall 2026 Edition

A full book of the Lab’s kind of problem, printed and sequenced. Lands 13 November.

Store opens 13 Nov

Search keywords: hard algebra 1 problems with answers, algebra challenge problems pdf, algebra puzzles with answers, writing expressions from words practice, five less than twice a number, algebra 1 enrichment, algebra 1 EOC practice, 9th grade algebra challenge, algerbra, algbra, expresions, sunny bun, bandit bun, solver society.