Welcome to "Pastry Carry Lab", a Grade 2 Regrouping within 1000 mission at the Seedling warm-up level, staged in a bakery scenario. The mission opens with a hands-on prompt: "Trade sugar cubes to add 158 and 24. First, build 1 bundles of 10 sugar cubes (a stand-in for the hundreds in 24)." Students work with the numbers 158, 24, 1 and reach a final answer of 1 across 3 guided steps.
Behind the story, this lesson builds regrouping within 1000 understanding aligned to CCSS 2.NBT.B.7. The key strategy is: 158 + 24 = 182.
A common misconception this page surfaces is: Skipping the hundreds column when subtracting. Every column must be touched, even if the digit looks small or matches. Walk the columns right to left. The adaptive Socratic hints move from a small nudge to a fuller strategy, keeping the reasoning visible for students, parents, and teachers.
Grade 2 · Regrouping within 1000
Mission Progress
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Thinking Summary · 1
Mastered[object Object]
[Discovery] Trade sugar cubes to add 158 and 24. First, build 1 bundles of 10 sugar cubes (a stand-in for the hundreds in 24).
1
Active StepDistribute items equally among groups
Everything you need to know about the Socratic experience.
Trade sugar cubes to add 158 and 24. First, build 1 bundles of 10 sugar cubes (a stand-in for the hundreds in 24). Hint: 24 has 1 hundreds. We sketch them as 1 bundles of 10.
How many column regroups (carries or borrows) did this addition require? If you get stuck, the adaptive hint is: Required regroups: 1.
Seedling missions anchor the visual model with small, friendly numbers — ideal as the first attempt at this topic. Within Grade 2 Regrouping within 1000, expect numbers in the corresponding range.
Skipping the hundreds column when subtracting. Every column must be touched, even if the digit looks small or matches. Walk the columns right to left.
Add/Subtract within 100 (Two-digit fluency is the substrate for three-digit regrouping.) Open /grade-2/addsubwithin100 to start that topic's missions.
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.
Research on "productive struggle" shows that 20–60 seconds of focused effort BEFORE help dramatically improves long-term retention — the brain encodes the strategy more deeply. Inquiry AI's hint timing is calibrated to this window: short enough to prevent frustration, long enough to lock in the learning. Parents can adjust the threshold in settings if a learner needs faster scaffolding.
