Learn with Amar
Teaching video
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Grade 4 chapters and video availability01 · Read and understand
What you will learn
- Split both factors into tens and ones using an area model.
- Explain your method and check what the result means in the stated situation.
Before you start
Multiplication and division facts, simple fractions, place value, and basic length and area measurement.
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 23 × 14.
Why this math matters
Count a rectangular grid with larger dimensions using smaller familiar products. 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.
Multiply two two-digit numbers
PausedQuestion: Start with the question. Paused.
Question
Start with the question
Find 23 × 14.
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
23 = 20 + 3; 14 = 10 + 4
Both sides of the area model are split.
Connect the parts
200 + 80 + 30 + 12
The four rectangles are 20×10, 20×4, 3×10, and 3×4.
State and check the result
23 × 14 = 322
Adding all four partial areas gives the full product.
The result
23 × 14 = 322
Adding all four partial areas gives the full product.
Common mistakes to catch
- Include every pair of expanded parts.
- The tens row in a written algorithm represents tens, not ones.
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 32 × 21.
Show a hint
Use 32 × 20 plus 32 × 1.
Reveal answer and explanation
672
640 + 32 = 672.
Practice 2
Why does multiplying only 20×10 and 3×4 miss part of 23×14?
Show a hint
The model has four pieces, not two.
Reveal answer and explanation
It omits 20×4 and 3×10
Those cross-parts contribute another 110 to the product.
Take the idea with you
Count a rectangular grid with larger dimensions using smaller familiar products.
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: Divide hundreds by sharing place values
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