$145\overset{m}{\mathop{\equiv }}\,68\Rightarrow m\left| 145-68 \right.\Rightarrow m\left| 77 \right.\xrightarrow{m\ne 1}m=7,11,77$ $160=2\times 77+6\Rightarrow 160\overset{77}{\mathop{\equiv }}\,6$ $7\left| 77 \right.\Rightarrow 160\overset{7}{\mathop{\equiv }}\,6$ $11\left| 77 \right.\Rightarrow 160\overset{11}{\mathop{\equiv }}\,6$ تذکر: فرض کنید $a\overset{b}{\mathop{\equiv }}\,r$ و $m\left| b \right.$، آن‌گاه داریم: $a\overset{b}{\mathop{\equiv }}\,r\Rightarrow a=bq+r\Rightarrow a=(m{q}')q+r=m{{q}_{1}}+r$ $\Rightarrow a\overset{m}{\mathop{\equiv }}\,r$