Learn with Amar
Teaching video
A teaching recording for this chapter has not been published yet. Start with the worked example below and explore the related animations where available.
Grade 2 chapters and video availability01 · Read and understand
What you will learn
- Regroup ten ones as one ten in two-digit addition.
- Explain your method and check what the result means in the stated situation.
Before you start
Counting and comparing whole numbers, basic addition and subtraction, and recognizing simple shapes.
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 jar has 38 beads and gains 27. How many beads now?
Why this math matters
Use place-value blocks to explain why written carrying preserves a total. 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.
Trade ten ones when adding
PausedQuestion: Start with the question. Paused.
Question
Start with the question
A jar has 38 beads and gains 27. How many beads now?
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
8 + 7 = 15 ones
The ones sum is more than nine.
Connect the parts
15 ones = 1 ten + 5 ones
Trade ten ones for a ten without changing the amount.
State and check the result
38 + 27 = 6 tens + 5 ones = 65
Three tens plus two tens plus the traded ten make six tens.
The result
38 + 27 = 6 tens + 5 ones = 65
Three tens plus two tens plus the traded ten make six tens.
Common mistakes to catch
- The carried 1 represents ten, not one extra unit.
- Do not forget to add the traded ten to the tens column.
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 46 + 18.
Show a hint
Regroup fourteen ones.
Reveal answer and explanation
64
Fourteen ones becomes one ten and four ones; the tens total six.
Practice 2
In 29 + 34, why does the tens total include an extra ten?
Show a hint
Nine plus four creates thirteen ones.
Reveal answer and explanation
Ten of the thirteen ones are traded
Two tens plus three tens plus that traded ten gives six tens and three ones.
Take the idea with you
Use place-value blocks to explain why written carrying preserves a total.
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: Subtract matching place values
Completion is your own study record, not a test score. It stays in this browser, does not sync to another device, and can be removed by clearing browser data.