## Thinking Mathematically (6th Edition)

$113_{four}$
Rightmost column: $1+2=3_{ten}=3\times1=_{}3_{four}$ record the 3 (no carry): $.\qquad \ \$ $.\qquad \ \ 31_{four}$ $.\quad +\ \ \ 22_{four}$ $.\quad \_\_\_\_$ $.\qquad \ \ \ \ 3_{four}$ Next column: $3+2=5=1\times4+1\times1=11_{four}$ record the 11: $.\qquad \ \$ $.\qquad \ \ 31_{four}$ $.\quad +\ \ \ 22_{four}$ $.\quad \_\_\_\_$ $.\qquad 113_{four}$ Check in base 10: $13+10=23$