Welcome to "Fuel Tank Reader", a Grade 3 Mass and Liquid Volume mission at the Seedling warm-up level, staged in a space scenario. The mission opens with a hands-on prompt: "The scale runs from 0 to 100 g in steps of 10. Mark the needle at 30 g." Students work with the numbers 0, 100, 10 and reach a final answer of 80 across 3 guided steps.
Behind the story, this lesson builds mass and liquid volume understanding aligned to CCSS 3.MD.A.2. The key strategy is: Ticks × 10 = reading.
A common misconception this page surfaces is: Treating g and kg as interchangeable without converting. 1 kg = 1000 g. You can only add/subtract once units match — convert first. The adaptive Socratic hints move from a small nudge to a fuller strategy, keeping the reasoning visible for students, parents, and teachers.
Grade 3 · Mass and Liquid Volume
Mission Progress
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Thinking Summary · 1
Mastered[object Object]
[Discovery] The scale runs from 0 to 100 g in steps of 10. Mark the needle at 30 g.
1
Active StepPlace the marker on 30.
3rd Grade Mass and Liquid Volume 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 number line to move from the story to a precise mass and liquid volume idea. Work through the prompts in order: notice the structure first, name the quantities, then check whether the final answer fits the original situation.
Common wrong turn: That's one tick early. Add another 10.
Common wrong turn: That's the tick COUNT. Multiply by 10 to get g.
Common wrong turn: That subtracts. We need the COMBINED mass.
In 3rd Grade Mass and Liquid Volume, students need to connect the story, the model, and the symbolic answer. The core move here is: Ticks × 10 = reading. A useful check is to ask whether the answer avoids this pitfall: Treating g and kg as interchangeable without converting. 1 kg = 1000 g. You can only add/subtract once units match — convert first.
Everything you need to know about the Socratic experience.
The scale runs from 0 to 100 g in steps of 10. Mark the needle at 30 g. Hint: Each tick equals 10 g. Count ticks from 0.
A second tank of coolant reads 50 g. Total = ? (in g) If you get stuck, the adaptive hint is: 30 + 50 = ?
Seedling missions anchor the visual model with small, friendly numbers — ideal as the first attempt at this topic. Within Grade 3 Mass and Liquid Volume, expect numbers in the corresponding range.
Treating g and kg as interchangeable without converting. 1 kg = 1000 g. You can only add/subtract once units match — convert first.
Bar Graph (Comparing measured masses naturally produces a bar-graph data set.) Open /grade-3/bargraph 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.
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.
