Learn with Amar
Teaching video
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Grade 3 chapters and video availability01 · Read and understand
What you will learn
- Regroup both ones and tens in three-digit addition.
- 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
Find 467 + 285.
Why this math matters
Use an expanded sum to explain every step of a multi-column addition. 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.
Add across two place-value trades
PausedQuestion: Start with the question. Paused.
Question
Start with the question
Find 467 + 285.
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
7 + 5 = 12: write 2 ones, trade 1 ten
Carry value into the next place.
Connect the parts
6 + 8 + 1 = 15 tens
Trade ten of those tens for one hundred, leaving five tens.
State and check the result
4 + 2 + 1 = 7 hundreds; total 752
All places include the values received from the place below.
The result
4 + 2 + 1 = 7 hundreds; total 752
All places include the values received from the place below.
Common mistakes to catch
- A carried digit changes unit between places.
- Do not discard a trade after writing the lower-place digit.
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
Find 358 + 476.
Show a hint
Both the ones and tens need trades.
Reveal answer and explanation
834
Fourteen ones leaves four; thirteen tens leaves three and adds one hundred.
Practice 2
Why must a carried ten be included before adding the tens column?
Show a hint
It came from the ones sum.
Reveal answer and explanation
Otherwise part of the original value is lost
The carry represents real value that moved places rather than disappeared.
Take the idea with you
Use an expanded sum to explain every step of a multi-column addition.
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: Regroup through an empty tens place
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