Thinking Summary · 1
MasteredVisual Logic: 0 of 1 parts shaded.
[Discovery] There were 11 satellites. Shade the 4 that were recalled — the unshaded parts are what remains.
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Active StepWelcome to "Fuel Leak Stopper", a 1st Grade Subtraction mission at the Explorer (core) level, staged in our space exploration scenario. The mission opens with a hands-on prompt: "There were 11 satellites. Shade the 4 that were recalled — the unshaded parts are what remains." You'll work with the numbers 11, 4, 7 and arrive at a final answer of 4 across 3 guided steps.
Behind the space exploration story, this lesson is really about subtraction aligned to CCSS 1.OA.A.1. Understanding subtraction as taking from, taking apart, and comparing — within 20. The key strategy this mission asks you to internalise: Start at 11, count back 4.
A general pattern to watch for in 1st Grade subtraction — illustrated with example numbers below, which may differ from this lesson's: Forgetting subtraction is the undo of addition. Play fact-family games: give 3+2=5 and ask for the matching subtraction facts. If you get stuck on "Fuel Leak Stopper", 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 1 · Subtraction
Mission Progress
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Thinking Summary · 1
MasteredVisual Logic: 0 of 1 parts shaded.
[Discovery] There were 11 satellites. Shade the 4 that were recalled — the unshaded parts are what remains.
1
Active Step1st Grade Subtraction explorer-2 representative practice page for students who need a crawlable, worked entry point into the topic without exposing every near-duplicate long-tail mission.
This explorer · core practice mission uses a fraction bar to move from the story to a precise subtraction idea. Work through the prompts in order: notice the structure first, name the quantities, then check whether the final answer fits the original situation.
In 1st Grade Subtraction, students need to connect the story, the model, and the symbolic answer. The core move here is: Start at 11, count back 4. A useful check is to ask whether the answer avoids this pitfall: Subtracting more than you have (e.g., 3 − 5). With physical objects, show it is impossible at Grade 1. Save negatives for later.
Everything you need to know about the Socratic experience.
There were 11 satellites. Shade the 4 that were recalled — the unshaded parts are what remains. Hint: Tap + until the bar has 11 parts, then tap 4 of them to mark them as recalled.
You know 4 + 7 = 11. So what is 11 − 7? If you get stuck, the adaptive hint is: One fact-family, three equations.
Explorer missions hit the core abstraction at typical numeric ranges — this is where conceptual mastery is built. Within 1st Grade Subtraction, expect numbers in the corresponding range.
Subtracting more than you have (e.g., 3 − 5). With physical objects, show it is impossible at Grade 1. Save negatives for later.
Comparing (Subtraction answers "how many more".). Open /grade-1/comparing to start that topic's missions.
Pure discovery is inefficient — kids hit a wall and quit. Guided Discovery scaffolds the path: a careful sequence of questions, models, and adaptive hints leads the learner toward the insight without revealing it. Inquiry AI's hint system fires automatically after ~15s of hesitation or on the first mistake, escalating from a Socratic nudge to a worked example only when needed. Mistakes are diagnosed via "misconception keys" so the hint matches the actual wrong-thinking pattern.
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.