Which is twenty thousand eight hundred twelve written with base-ten numerals

The answer is 20812

The numeral system we use is a base ten numeral system. Base ten numeral numbers are: 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9.

The number has:

2 "tens thousands" = 2 * 10000 = 20000

0 "thousands" = 0

8 "hundreds " = 8 * 100 = 800

1 "tens" = 1 * 10 = 10

2 "ones" = 2 * 1 = 2

Sum all the results = > 20000+800+10+2 = 20812

That is how you write a number using base ten numerals (numbers from 0 to 9)