Answer
110010111
Work Step by Step
We repeatedly divide 407 by 2, writing the result under the number and writing the remainder to the right of that number. When we read the remainders from the bottom up, we get our answer.
$2|\underline{407}\ \ \ $ remainders
$2|\underline{203}\ \ \ \ \ 1$
$2|\underline{101}\ \ \ \ \ 1$
$2|\underline{50}\ \ \ \ \ \ \ 1$
$2|\underline{25}\ \ \ \ \ \ \ 0$
$2|\underline{12}\ \ \ \ \ \ \ 1$
$2|\underline{6}\ \ \ \ \ \ \ \ 0$
$2|\underline{3}\ \ \ \ \ \ \ \ 0$
$2|\underline{1}\ \ \ \ \ \ \ \ 1$
$2|\underline{0}\ \ \ \ \ \ \ \ 1\ \ \uparrow\ $read digits up
