Welcome to "Fuel Pod Decade Stacker", a 1st Grade Tensadd mission at the Seedling (entry-level) level, staged in our space exploration scenario. The mission opens with a hands-on prompt: "First batch: 3 shuttles of 10 cadets (30 cadets). Second batch: 1 more shuttle of 10 (10 cadets). Build BOTH batches as ten-bundles." You'll work with the numbers 3, 10, 30 and arrive at a final answer of 50 across 3 guided steps.
Behind the space exploration 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 "Fuel Pod Decade 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: 3 shuttles of 10 cadets (30 cadets). Second batch: 1 more shuttle of 10 (10 cadets). Build BOTH batches as ten-bundles.
1
Active StepDistribute items equally among groups
1st Grade Tensadd seedling-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 seedling · gentle warm-up mission uses a equal-groups model to move from the story to a precise tensadd 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 Tensadd, students need to connect the story, the model, and the symbolic answer. The core move here is: Adding tens is just like adding ones — but each unit is worth 10. A useful check is to ask whether the answer avoids this pitfall: 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.
Everything you need to know about the Socratic experience.
First batch: 3 shuttles of 10 cadets (30 cadets). Second batch: 1 more shuttle of 10 (10 cadets). Build BOTH batches as ten-bundles. Hint: Tap "+ Add Group" 4 times. Each group gets exactly 10.
One more bundle of 10 cadets arrives. What is the new total now? If you get stuck, the adaptive hint is: 40 + 10 = ?
Seedling missions anchor the visual model with small, friendly numbers — ideal as the first attempt at this topic. 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.
Addition (Same join-and-count logic, scaled up to ten-bundles.). Open /grade-1/addition to start that topic's missions.
Socratic teaching answers a question with a better question. Instead of "the answer is 12", the system asks "if you had 3 groups of 4, how could you skip-count?" The goal is to externalize the learner's reasoning so they hear themselves think. Every Inquiry AI hint follows this pattern: nudge → reframe → analogy → only then a worked example, in that order.
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.
