M3.1.8 For the adult
Powers of ten
How many zeros are there in ten million, and is there a short way to write it?
What this chapter teaches
A power of ten is 10 with an index. The index counts the zeros after the 1, so 10⁶ is 1 000 000. A lakh is 100 000 and a crore is 10 000 000 in the places that use those names.
Three questions to ask
There is no one right wording. Listen for the idea.
- How many zeros are there in one million, and how can you write it as a power of ten?
- How many lakh make one crore?
- Which is bigger, 3 × 10⁶ or 8 × 10⁵, and how do you know?
After the chapter, the learner can
- Write 1 000 as 10³ and 1 000 000 as 10⁶
- Say 10 000 000 as ten million or one crore
- Use powers of ten to compare very big numbers
What they copy into their notebook
10³ = 1 000, 10⁶ = 1 000 000. The index counts the zeros. 10 000 000 is ten million, or one crore. 100 000 is one hundred thousand, or one lakh. A bigger index means a bigger number.