Question

I'm confused, can someone help me?

Answer 1

$\bf \begin{array}{rll} \stackrel{standard}{notation}&\stackrel{scientific}{notation}\\ \cline{1-2} 7000&7\times 10^3\\ 700&7\times 10^2\\ 70&7\times 10^1\\\\ \boxed{7}&\boxed{7\times 10^0}\\\\ 0.7&7\times 10^{-1}\\ 0.07&7\times 10^{-2}\\ 0.007&7\times 10^{-3} \end{array}$

recall, for the scientific notation, it has to be using some power of 10, and the exponent of the base 10, is how many slots you're away from the decimal point.  0.007 uses 10⁻³ because 7.0 or 7. when we make it 0.007, we have to move the decimal point from in front of the 7 3 slots over to the left.  Likewise, the 7000 is using 10³, because we moved the dot from 7. to 7000. , namely 3 slots to the right.

the missing value is there in the middle, notice is "7".

well, we can say that 7 is using 10⁰, however most of the time the 10⁰ is omitted and we settle for 7 alone, however scientific notation wise, that'd be it.