My mum's a teacher and she found thid really cool way of multiplying decimals in a teaching book. In the book it calls it 'Italian'.
Step 1: Table
Set out a rectangle like this:
(The dots are decimal points)
(The diagonal lines are important)
Step 2: Tens
(If the product of the two numbers is less than 10, leave this half blank)
Step 3: Digits
Step 4: Magic!
Step 5: Decimal Point
So the answer is 164.68!
Try with other numbers and enjoy "cheating" on your maths questions.