We are going to round the number '3'.
Look at the first number to the right of '3', which is '9'.
That number is greater than '5', so you round the '3' to '4', and add three zeros after '4'.
Answer is: 4,000
Answer:
2200
Step-by-step explanation:

x

1 x 5 = 5
16 x 4 = 64
is the answer
In simplest form the answer would be

because it cant be divided any farther.
21 hundred million,64 thousand, and 50