10 percent of 21000000 is 2100000.
2.1 x 10^7
It is: 2.1*10^7
210000000
2.1 X 10^7 The zeros are superfluous.
21000000
21,000,000 is twenty one million.
350,000 hours.
3000000 x 7 = 21000000
42000
at least
it is worth $21000000
Two hundred ten thousand.