Let's break it down into something more simple:
What's 10 times 10? 100
What's 10 times 10 times 10? 1000
Do you see a pattern? (Cool trick - The number of 10s match the number of 0s in the answer)
We have seven 0s in our answer, so let's check:
10 x 10 x 10 x 10 x 10 x 10 x 10 = 10,000,000
An exponent tells us that we're multiplying the big number by itself however many times the little number in the corner tells us.
So if we multiply 10 by itself 7 times (what we did above), then our answer will be 10 to the power of 7, or . This is equal to 10,000,000.