Step-by-step explanation:
a number is a sequence of digits with every position being multiplied by increasing powers of 10.
and the whole number is then the sum of of these little multiplications.
the first position left of the decimal point is for 10⁰ (1). the second position is 10¹ (10). the third position for 10² (100). and so on.
the given number is therefore just the short version of
7×10⁴ + 0×10³ + 8×10² + 1×10¹ + 9×10⁰
and therefore, the digit 1 in this number has the value 1×10¹ = 10, which is also the place value, 10¹ = 10.
