Question

Convert $(231{)}_8$ into decimal system.

Answer 1

$(231{)}_8$ the value of the position of each of the numbers (as in decimal system) is
$1=8^{\circ }\times 1$
$3=8^1\times 3$
$2=8^2\times 2$
Hence $(231{)}_8=(8^{\circ }\times 1+8^1\times 3+8^2\times 2{)}_{10}$
$(231{)}_8=(1+24+128{)}_{10}$
$(231{)}_8=(153{)}_{10}$