A numerical series in the Indian number system is given as Thousand, Ten thousand, Lakh, Ten lakh, ?. Choose the term that correctly completes this ascending sequence of place values.

Introduction / Context:
This question examines understanding of the Indian place value system. The series lists names of place values in increasing order. The learner must recall how the Indian system proceeds from Thousand upwards and then choose the correct next unit after Ten lakh. This concept appears frequently in school mathematics and quantitative aptitude questions.

Given Data / Assumptions:

Given series: Thousand, Ten thousand, Lakh, Ten lakh, ? We are using the Indian number system, not the international system. Options include smaller and larger place values for contrast. The sequence clearly moves from smaller to larger values.

Concept / Approach:
In the Indian number system, counting proceeds as Ones, Tens, Hundreds, Thousands, Ten thousands, Lakhs, Ten lakhs, Crores, Ten crores, and so on. The given series starts at Thousand (10^3), then Ten thousand (10^4), then Lakh (10^5), then Ten lakh (10^6). The next place value is Crore (10^7). Therefore, the learner must choose Crore to continue the ascending pattern correctly. Smaller units like Ones and Hundred obviously do not fit after larger ones like Ten lakh.

Step-by-Step Solution:
Step 1: Recall the order of place values in the Indian number system: Thousand, Ten thousand, Lakh, Ten lakh, Crore, Ten crore, and so on. Step 2: Understand that Thousand represents 1,000, Ten thousand represents 10,000, Lakh represents 1,00,000, and Ten lakh represents 10,00,000. Step 3: The next place value after Ten lakh is Crore, which represents 1,00,00,000. Step 4: Examine the options. Ones and Hundred are much smaller than Thousand and thus cannot follow Ten lakh in an ascending series. Step 5: Ten crore is 10,00,00,000, which is two steps beyond Ten lakh, so it skips a value in the sequence. Step 6: Million belongs to the international number system, not the Indian place value sequence explicitly used here. Step 7: Therefore, Crore is the correct next term after Ten lakh.

Verification / Alternative check:
As an alternative check, convert each term to a power of ten. Thousand is 10^3, Ten thousand is 10^4, Lakh is 10^5, Ten lakh is 10^6. The next integer power is 10^7, which in the Indian system is named Crore. Ten crore corresponds to 10^8 and therefore would be the next term after Crore, not immediately after Ten lakh. This confirms that Crore is the unique correct continuation of the series.

Why Other Options Are Wrong:
Ones is wrong because it represents 10^0 and is far smaller than a Lakh or a Ten lakh. Hundred is wrong because it represents 10^2 and also lies below Thousand, not above Ten lakh. Ten crore is wrong because it jumps beyond Crore and does not come immediately after Ten lakh. Million is wrong in this context because it belongs to the international system and is not the direct translation of the next Indian place value after Ten lakh in this series.

Common Pitfalls:
Students sometimes mix up the Indian and international systems, confusing Crore with Million or Billion. Another common error is to see a larger looking name like Ten crore and choose it without checking whether it is the immediate next step in the sequence. Remembering the standard chain Thousand, Ten thousand, Lakh, Ten lakh, Crore, Ten crore helps keep the order clear in exam questions.

Final Answer:
The place value that completes the series is Crore.