Welcome to "Flour Sack Weigh-In", a Grade 3 Mass and Liquid Volume mission at the Explorer core practice level, staged in a bakery scenario. The mission opens with a hands-on prompt: "The scale runs from 0 to 500 g in steps of 50. Mark the needle at 150 g." Students work with the numbers 0, 500, 50 and reach a final answer of 400 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 × 50 = reading.
A common misconception this page surfaces is: Confusing mass (how heavy) with volume (how much space). 1 L of water and 1 L of air have very different masses but the same volume. Different questions, different scales. 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 500 g in steps of 50. Mark the needle at 150 g.
1
Active StepPlace the marker on 150.
3rd Grade Mass and Volume explorer-1 representative practice page for students who need a crawlable, worked entry point into the topic without exposing every near-duplicate long-tail mission.
This explorer · core practice mission uses a number line to move from the story to a precise mass and 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 50.
Common wrong turn: That's the tick COUNT. Multiply by 50 to get g.
Common wrong turn: That subtracts. We need the COMBINED mass.
In 3rd Grade Mass and Volume, students need to connect the story, the model, and the symbolic answer. The core move here is: Ticks × 50 = reading. A useful check is to ask whether the answer avoids this pitfall: Confusing mass (how heavy) with volume (how much space). 1 L of water and 1 L of air have very different masses but the same volume. Different questions, different scales.
