a 3 a 2 a 1 a 0 = ( a 3 × b 3 ) + ( a 2 × b 2 ) + ( a 1 × b 1 ) + ( a 0 × b 0 ) {\displaystyle a_{3}a_{2}a_{1}a_{0}=(a_{3}\times b^{3})+(a_{2}\times b^{2})+(a_{1}\times b^{1})+(a_{0}\times b^{0})} (Note that a 3 a 2 a 1 a 0 {\displaystyle a_{3}a_{2}a_{1}a_{0}} represents a sequence of digits, not multiplication)