Welcome to "Donut Tray Stacker", a 1st Grade Tensadd mission at the Explorer (core) level, staged in our bakery scenario. The mission opens with a hands-on prompt: "First batch: 4 trays of 10 cookies (40 cookies). Second batch: 4 more trays of 10 (40 cookies). Build BOTH batches as ten-bundles." You'll work with the numbers 4, 10, 40 and arrive at a final answer of 90 across 3 guided steps.
Behind the bakery story, this lesson is really about tensadd aligned to CCSS 1.NBT.C.4. Add multiples of 10 within 100 — when you add tens, the ones digit never changes. The key strategy this mission asks you to internalise: Adding tens is just like adding ones — but each unit is worth 10.
A general pattern to watch for in 1st Grade tensadd — illustrated with example numbers below, which may differ from this lesson's: Changing the ones digit when adding tens (e.g., 23 + 10 = 34). Adding 10 only changes the tens digit. The ones stay put. Show with base-10 blocks. If you get stuck on "Donut Tray Stacker", 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 · Tensadd
Mission Progress
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Thinking Summary · 1
Mastered[object Object]
[Discovery] First batch: 4 trays of 10 cookies (40 cookies). Second batch: 4 more trays of 10 (40 cookies). Build BOTH batches as ten-bundles.
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Active StepDistribute items equally among groups
Everything you need to know about the Socratic experience.
First batch: 4 trays of 10 cookies (40 cookies). Second batch: 4 more trays of 10 (40 cookies). Build BOTH batches as ten-bundles. Hint: Tap "+ Add Group" 8 times. Each group gets exactly 10.
One more bundle of 10 cookies arrives. What is the new total now? If you get stuck, the adaptive hint is: 80 + 10 = ?
Explorer missions hit the core abstraction at typical numeric ranges — this is where conceptual mastery is built. Within 1st Grade Tensadd, expect numbers in the corresponding range.
Forgetting the trailing zero (e.g., 30 + 40 = 7). 3 tens + 4 tens = 7 TENS, not 7 ones. The unit must travel through the answer.
Place Value (Adding tens IS place value in motion — the tens column drives the change.). Open /grade-1/place-value 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.
