1. The problem is unclear as stated, but it seems you want to use the digits 1, 1, 2, and 2 each exactly once, possibly to form a number or expression with one decimal point. 2. Let's consider forming a decimal number using these digits exactly once each, with one decimal point. 3. Possible numbers include $1.122$, $1.212$, $1.221$, $2.112$, $2.121$, $2.211$. 4. Each number uses digits 1, 1, 2, 2 exactly once and has one decimal point. 5. If you want the smallest such number, it is $1.122$. 6. If you want the largest, it is $2.211$. 7. Please clarify if you want a specific operation or arrangement. Final answer: One example number using digits 1, 1, 2, 2 with one decimal point is $1.122$.