Explanation:
Step 1: Write down the whole number with a decimal point and trailing zeros to match the place values of the other numbers.
1212.0000
Step 2: Add the first decimal number (1212.0000 + 17.0005). Align the decimal points carefully.
1212.0000
+17.0005
___________
1229.0005
Step 3: Subtract the second decimal number from the result (1229.0005 - 9.1102). Align the decimal points and borrow across columns where necessary.
1229.0005
-9.1102
___________
1219.8903
Final Answer = 1219.8903