Learn with Amar
Teaching video
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Grade 3 chapters and video availability01 · Read and understand
What you will learn
- Convert kilograms to grams before adding masses.
- Explain your method and check what the result means in the stated situation.
Before you start
Place value through hundreds, addition and subtraction, equal groups, and equal shares.
Keep paper nearby. Read the question once for the context, then again to identify what is known and what you need to find.
Start with a question
A bag contains 2 kg of sand and another holds 350 g. What is their combined mass in grams?
Why this math matters
Compare package masses using one common unit. The worked example shows how to connect the situation, its mathematical representation, and a check on the result.
Set up the model
A useful answer starts with clear assumptions:
- Use the units, grouping rules, and reference whole stated in the question.
- Treat the supplied counts and measurements as exact within the classroom model, unless an estimate or a random outcome is requested.
02 · Work through the example
Follow the reasoning, one step at a time.
Try to predict the next step before reading it. After each calculation, explain why the operation makes sense and how it helps answer the original question.
Work through it with Amar
See this example unfold.
The complete worked example, one idea at a time.
Combine mass measurements
PausedQuestion: Start with the question. Paused.
Question
Start with the question
A bag contains 2 kg of sand and another holds 350 g. What is their combined mass in grams?
Before you calculate
Read what is known and what you need to find. Make a prediction before moving to the first calculation.
Starts paused. Play advances through the full text at a reading pace; pause whenever you need more time. Previous, Next, and the phase buttons let you set your own pace. Playback pauses when this walkthrough leaves the screen or you switch tabs.
Your device’s reduced-motion setting keeps each phase still. Manual controls remain available. The full written solution stays below.
Represent the situation
1 kg = 1,000 g
The prefix kilo represents one thousand.
Connect the parts
2 kg = 2,000 g
Convert the kilogram part.
State and check the result
2,000 + 350 = 2,350 g
Both amounts now use the same unit.
The result
2,000 + 350 = 2,350 g
Both amounts now use the same unit.
Common mistakes to catch
- Mass units must match before numerical addition.
- A gram and a kilogram differ by a factor of one thousand.
03 · Practice independently
Try it before revealing the answer.
Use paper or a calculator as needed. Write your units and reasoning, then open the hint or explanation to check your approach.
Practice 1
How many grams are in 3 kg?
Show a hint
Use one thousand grams per kilogram.
Reveal answer and explanation
3,000 g
3 × 1,000 = 3,000.
Practice 2
Which is heavier: 950 g or 1 kg?
Show a hint
Rename the kilogram in grams.
Reveal answer and explanation
1 kg
1,000 g exceeds 950 g by 50 g.
Take the idea with you
Compare package masses using one common unit.
04 · Reflect and continue
Can you explain it in your own words?
Before moving on, explain the main idea without looking at the worked example. Try both practice questions, check your reasoning, and name one mistake you now know how to avoid. Return to a step if you still need support.
Up next: Compare liquid capacities
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