900,000,000,000 in standard form is written as 9 x 10^11. This is because the decimal point is moved 11 places to the left to make the number between 1 and 10, and the exponent indicates how many places the decimal point was moved.
The standard form is 41,800,000
3,400,000.
75
200,000,000,000
Five hundredths in standard form is 5.0 × 10-2
The standard form is 41,800,000
21.59 in standard form is 2.159 × 101
Writing a number in standard form simply means to express the number in its 'normal' form. Therefore, your example is written in standard form.
3,400,000.
75
60,000
200,000,000,000
0.012
165,000,000
4,600,000
0.006
100,000,000,000,000