The highest power of 12 that divides 273 (with remainder) is [tex]12^2=144[/tex], and dividing gives
[tex]273=1(144)+129[/tex]
Divide the remainder term by the next highest power of 12, [tex]12^1=12[/tex].
[tex]129=10(12)+9[/tex]
So [tex]273_{10}=1a9_{12}[/tex], since
[tex]273=1\cdot144+10\cdot12+9\cdot1=1\cdot12^2+10\cdot12^1+9\cdot12^0[/tex]
