Thinking Summary · 1
MasteredVisual Logic: 0 of 1 parts shaded.
[Discovery] There were 11 donuts. Shade the 5 that were eaten — the unshaded parts are what remains.
1
Active StepWelcome to "Pie Portioner", a 1st Grade Subtraction mission at the Challenger (stretch) level, staged in our bakery scenario. The mission opens with a hands-on prompt: "There were 11 donuts. Shade the 5 that were eaten — the unshaded parts are what remains." You'll work with the numbers 11, 5, 6 and arrive at a final answer of 5 across 3 guided steps.
Behind the bakery 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 5.
A general pattern to watch for in 1st Grade subtraction — illustrated with example numbers below, which may differ from this lesson's: Subtracting more than you have (e.g., 3 − 5). With physical objects, show it is impossible at Grade 1. Save negatives for later. If you get stuck on "Pie Portioner", 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
0/3
Thinking Summary · 1
MasteredVisual Logic: 0 of 1 parts shaded.
[Discovery] There were 11 donuts. Shade the 5 that were eaten — the unshaded parts are what remains.
1
Active StepEverything you need to know about the Socratic experience.
There were 11 donuts. Shade the 5 that were eaten — the unshaded parts are what remains. Hint: Tap + until the bar has 11 parts, then tap 5 of them to mark them as eaten.
You know 5 + 6 = 11. So what is 11 − 6? If you get stuck, the adaptive hint is: One fact-family, three equations.
Challenger missions push beyond CCSS expectations with edge cases that surface deeper misconceptions. Within 1st Grade Subtraction, expect numbers in the corresponding range.
Mixing up the order: writing 2 − 5 instead of 5 − 2. In Grade 1, subtraction is NOT commutative. The bigger number goes first.
Addition (Partner operation — same fact-family.). Open /grade-1/addition to start that topic's missions.
Inquiry-based learning starts with a question, not a formula — students explore, hypothesize, and verify before being told the rule. In Inquiry AI, every mission opens with a "Discovery" step (manipulate the model), then "Abstraction" (write the equation), then "Reflect" (apply to a new case). The procedure is never given upfront; learners derive it from their own observations.
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.