Welcome to "Donut Rack Calculator", a 4th Grade Multidigitmult mission at the Challenger (stretch) level, staged in our bakery scenario. The mission opens with a hands-on prompt: "Decompose 48 × 23 into place-value parts and fill each cell of the partial-products box." You'll reason about the numbers 48, 23 across 3 guided steps.
Behind the bakery story, this lesson is really about multidigitmult aligned to CCSS 4.NBT.B.5. Multiply a whole number of up to four digits by a one-digit number, and multiply two two-digit numbers, using strategies based on place value. The key strategy this mission asks you to internalise: 48 × 23 = ?
A general pattern to watch for in 4th Grade multidigitmult — illustrated with example numbers below, which may differ from this lesson's: Multiplying only ones × ones and tens × tens (skipping the cross terms). The area model has *four* boxes for a reason. Every digit on top must meet every digit on the bottom. If you get stuck on "Donut Rack Calculator", 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 4 · Multidigitmult
Mission Progress
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Thinking Summary · 1
Mastered[object Object]
[Discovery] Decompose 48 × 23 into place-value parts and fill each cell of the partial-products box.
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Active StepDecompose 48 × 23 into place-value parts. Fill each cell, then sum.
| × 40 | × 8 | |
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| 20 × | ||
| 3 × |
Everything you need to know about the Socratic experience.
Decompose 48 × 23 into place-value parts and fill each cell of the partial-products box. Hint: Break 48 into tens + ones, 23 into tens + ones, then multiply each pair.
Does 23 × 48 give the same answer as 48 × 23? If you get stuck, the adaptive hint is: Same factors, same product, regardless of order.
Challenger missions push beyond CCSS expectations with edge cases that surface deeper misconceptions. Within 4th Grade Multidigitmult, expect numbers in the corresponding range.
Misaligning partial products before summing. Use graph paper or column lines. Partial products live in different place-value columns and must stack accordingly.
Longdivision (Inverse partner — division uses the same place-value strategy in reverse.). Open /grade-4/longdivision 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.
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.
