Only on digit may be to the left of the decimal point. The mantissa must be a number in the interval [0, 10).
One digit
There should be exactly one digit.
One: no more and no fewer. And it cannot be a zero.
Only one non-zero digit.
Just remember that there is one digit to the left of the decimal in scientific notation. All the other digits go on the right of the decimal. Then find an appropriate power of ten to write the rest of the number. Your 3,400 in scientific notation is 3.4 x 104in scientific notation.
One
one
One digit
There should be exactly one digit.
If you want to have it in standard format, only one.
One: no more and no fewer. And it cannot be a zero.
In scientific notation, you should have only one digit to the left of the decimal point.
Only one non-zero digit.
There should be 1 non-zero digit.
Only one digit. The mantissa must be in the interval [1, 10).
Writing a string of random digits is a proper waste!
Just remember that there is one digit to the left of the decimal in scientific notation. All the other digits go on the right of the decimal. Then find an appropriate power of ten to write the rest of the number. Your 3,400 in scientific notation is 3.4 x 104in scientific notation.