what is the binary representation of 2015 ?
$$\begin{array}{rcrr}
& & \rm{q o u t i e n t} & \rm{r e m a i n d e r} \\
2015 & : 2 = & 1007 & 1 \\
1007 & : 2 = & 503 & 1 \\
503 & : 2 = & 251 & 1 \\
251 & : 2 = & 125 & 1 \\
125 & : 2 = & 62 & 1 \\
62 & : 2 = & 31 & 0 \\
31 & : 2 = & 15 & 1 \\
15 & : 2 = & 7 & 1 \\
7 & : 2 = & 3 & 1 \\
3 & : 2 = & 1 & 1 \\
1 & : 2 = & 0 & \textcolor[rgb]{1,0,0}{1} \\
\end{array}$$
$$2015_2~=~\textcolor[rgb]{1,0,0}{1}~1~1~1~1~0~1~1~1~1~1$$
2015 in binary is 11111011111
I do not know of an easy way to explain why 2015 in binary is 11111011111; however, I found a video that can explain it way better than I can. Here is the web address: https://www.khanacademy.org/math/pre-algebra/applying-math-reasoning-topic/alternate-number-bases/v/number-systems-introduction
Here's a detailed breakdown of the steps needed to turn 2015 decimal into binary:
.
I am going to say the same as Alan and the video clip LOL
1024 is the biggest power of 2 that goes into 2015, so I will start there
2015
= 1024 with 991 remaining
=1024+512+479 remaining
=1024+512+256+223 remaining
=1024+512+256+128+95remaining
=1028+512+256+128+64+31remaining
=1028+512+256+128+64+16+15remaining
=1028+512+256+128+64+16+8+7remaining
=1028+512+256+128+64+16+8+4+3remaining
=1028+512+256+128+64+16+8+4+2+1
$$\\=2^{10}+2^9+2^8+2^7+2^6\qquad+2^4+2^3+2^2+2^1+2^0\\
=11111011111$$
Of course you could just use this converter
http://www.binaryhexconverter.com/decimal-to-binary-converter
what is the binary representation of 2015 ?
$$\begin{array}{rcrr}
& & \rm{q o u t i e n t} & \rm{r e m a i n d e r} \\
2015 & : 2 = & 1007 & 1 \\
1007 & : 2 = & 503 & 1 \\
503 & : 2 = & 251 & 1 \\
251 & : 2 = & 125 & 1 \\
125 & : 2 = & 62 & 1 \\
62 & : 2 = & 31 & 0 \\
31 & : 2 = & 15 & 1 \\
15 & : 2 = & 7 & 1 \\
7 & : 2 = & 3 & 1 \\
3 & : 2 = & 1 & 1 \\
1 & : 2 = & 0 & \textcolor[rgb]{1,0,0}{1} \\
\end{array}$$
$$2015_2~=~\textcolor[rgb]{1,0,0}{1}~1~1~1~1~0~1~1~1~1~1$$