Place Value Problem: Converting 1 Hundred, 2 Tens, and 9 Ones to Standard Form

Q: Why can't I just write the digits in order: 1, 2, 9?

You absolutely can! Writing them in order gives you 129, which is the correct answer. The key is understanding that position matters - the first digit represents hundreds, not ones.

Q: What if I get confused about which place value is which?

Remember the pattern: ones, tens, hundreds from right to left. You can also think of it as 1, 10, 100 - each place is 10 times bigger than the one to its right!

Q: How do I check if 129 is really correct?

Break it down: 129 = 100 + 20 + 9. This gives you 1 hundred, 2 tens, and 9 ones - exactly what the problem asked for!

Q: What happens if there are zeros in some place values?

Zeros are placeholders! If you had 1 hundred, 0 tens, and 5 ones, you'd get 105. The zero shows there are no tens, but it keeps the hundreds and ones in the right positions.

Q: Is there a faster way to solve this?

Yes! Once you understand place value, you can read the digits directly: 1 hundred, 2 tens, 9 ones becomes 129. Just remember - order matters from left to right!

Place Value Conversion with Standard Form

Number of ones: 9

Number of tens: 2

Number of hundreds: 1

Determine the correct number according to the above place values:

❤️ Continue Your Math Journey!

We have hundreds of course questions with personalized recommendations + Account 100% premium

Step-by-step video solution

Watch the teacher solve the problem with clear explanations

00:00 Find the number

00:03 Place the digits in the appropriate position according to the given data,

00:06 and this is the solution to the question

Step-by-step written solution

Follow each step carefully to understand the complete solution

Understand the problem

Number of ones: 9

Number of tens: 2

Number of hundreds: 1

Determine the correct number according to the above place values:

Step-by-step solution

To solve this problem, we'll follow these steps:

Identify the contribution of each place value.
Sum these contributions to determine the resulting number.

Now, let's work through each step:

Step 1: Identify the contribution of each place value
We are given the number of ones, tens, and hundreds as follows:

Number of ones = 9, so this contributes $9 \times 1 = 9$ .
Number of tens = 2, so this contributes $2 \times 10 = 20$ .
Number of hundreds = 1, so this contributes $1 \times 100 = 100$ .

Step 2: Sum these contributions to determine the resulting number
The total value is calculated by summing these contributions:
$(1 \times 100) + (2 \times 10) + (9 \times 1) = 100 + 20 + 9 = 129$ .

Therefore, the number corresponding to the given place values is $129$ .

Final Answer

129

Key Points to Remember

Essential concepts to master this topic

Place Value Rule: Each position represents ten times the position to its right
Calculation Method: Multiply digit by place value: 1×100 + 2×10 + 9×1
Verification: Count total value matches standard form: 100+20+9=129 ✓

Common Mistakes

Avoid these frequent errors

Adding digits without considering place value
Don't just add 1+2+9=12! This ignores that each digit has different place values (hundreds, tens, ones). The hundreds digit contributes 100, not 1. Always multiply each digit by its place value first.

Practice Quiz

Test your knowledge with interactive questions

Determine the numerical value of the shaded area:

FAQ

Everything you need to know about this question

Why can't I just write the digits in order: 1, 2, 9?

You absolutely can! Writing them in order gives you 129, which is the correct answer. The key is understanding that position matters - the first digit represents hundreds, not ones.

What if I get confused about which place value is which?

Remember the pattern: ones, tens, hundreds from right to left. You can also think of it as 1, 10, 100 - each place is 10 times bigger than the one to its right!

How do I check if 129 is really correct?

Break it down: 129 = 100 + 20 + 9. This gives you 1 hundred, 2 tens, and 9 ones - exactly what the problem asked for!

What happens if there are zeros in some place values?

Zeros are placeholders! If you had 1 hundred, 0 tens, and 5 ones, you'd get 105. The zero shows there are no tens, but it keeps the hundreds and ones in the right positions.

Is there a faster way to solve this?

Yes! Once you understand place value, you can read the digits directly: 1 hundred, 2 tens, 9 ones becomes 129. Just remember - order matters from left to right!

🌟 Unlock Your Math Potential

Get unlimited access to all 18 Decimal Fractions - Basic questions, detailed video solutions, and personalized progress tracking.

📹

Unlimited Video Solutions

Step-by-step explanations for every problem

📊

Progress Analytics

Track your mastery across all topics

🚫

Ad-Free Learning

Focus on math without distractions

No credit card required • Cancel anytime