Welcome to "Cargo Algebra Lab", a 6th Grade Expressions mission at the Explorer (core) level, staged in our space exploration scenario. The mission opens with a hands-on prompt: "Use algebra tiles to build the expression 9x + 4." You'll reason about the numbers 9, 4, 5 across 3 guided steps.
Behind the space exploration story, this lesson is really about expressions aligned to CCSS 6.EE.A.2. Write, read, and evaluate expressions in which letters stand for numbers. The key strategy this mission asks you to internalise: Answer: 49.
A general pattern to watch for in 6th Grade expressions — illustrated with example numbers below, which may differ from this lesson's: Translating "3 less than n" as "3 - n" instead of "n - 3". "Less than" REVERSES the order. "3 less than 10" = 10 - 3 = 7. If you get stuck on "Cargo Algebra Lab", the adaptive Socratic hints below escalate from a gentle nudge to a worked-out strategy — the same way a one-on-one tutor would coach you through it.
Grade 6 · Expressions
Mission Progress
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Thinking Summary · 1
Mastered[object Object]
[Discovery] Use algebra tiles to build the expression 9x + 4.
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Active StepBuild 9x + 4 using x-tiles and 1-tiles.
Everything you need to know about the Socratic experience.
Use algebra tiles to build the expression 9x + 4. Hint: Each x-tile counts as one x. Each 1-tile is a unit. You need 9 x-tiles and 4 1-tiles.
In the expression 9x + 4, what is the constant? If you get stuck, the adaptive hint is: Answer: 4.
Explorer missions hit the core abstraction at typical numeric ranges — this is where conceptual mastery is built. Within 6th Grade Expressions, expect numbers in the corresponding range.
Forgetting to follow PEMDAS when evaluating. Substitute first, then evaluate using PEMDAS. Multiplication before addition.
Equations (Equations come from setting expressions equal.). Open /grade-6/equations to start that topic's missions.
C-P-A is the Singapore Math sequence proven to deepen number sense: first manipulate physical objects (Concrete), then draw pictures of them (Pictorial), and only then write equations (Abstract). Inquiry AI structures every mission as exactly these three steps — a manipulative, a picture/grid model, and finally the equation. Skipping straight to symbols is the #1 cause of math anxiety; the platform refuses to do it.
Yes. Every mission, handbook page, and topic hub is mapped to a specific CCSS code (visible in the page header). The curriculum follows the CCSS coherence map: Grade 1 number sense → Grade 3 multiplicative thinking → Grade 6 ratio reasoning, with each grade building strictly on the prior year's foundations.
