Answer
$1000_{\text{two}}$
Work Step by Step
The place values of base two are: $,,,, 2^3, 2^2, 2^1, 1$.
The place value that are less then $8$ are $2^3, 2^2, 2^1$ and $1$
Divide $8$ by $2^3$ or $8$ to obtain:
$8 \div 8 = 1$ remainder $0$
Divide the remainder $0$ by $2^1$ or $2$ to obtain:
$0 \div 2 = 0$ remainder $0$
Divide $0$ by $1$ to obtain
$0 \div 1= 0$
Thus,
$8=(1 \times 2^3) + (0 \times 2^2) + (0 \times 2) + (0 \times 1)
\\8=1000_{\text{two}}$