Writing a number in standard form simply means to express the number in its 'normal' form. Therefore, your example is written in standard form.
209 + 300 = 509
That IS the standard form.
You write 20.7 in standard form as: 2.07 × 101
67.24 is the standard form.
It is already in standard form.
509/100
209 + 300 = 509
How do write 666 in standard form?
It is already in standard form.
That is the standard form!
That IS the standard form.
That is the standard form.
You write 20.7 in standard form as: 2.07 × 101
You write 6.11 in standard form as 6.11 × 100
You write 7.54103 in standard form as 7.54103 × 100
You write 83,539,131 in standard form as 8.3539131 × 107
7.509 814 362 * 106