Multiply decimals in the same way you multiply whole numbers, then add up the number of digits after decimal points and that number tells the number of decimal places has the answer.
To solve the given multiplication:
1. Multiply first 2 numbers:
2. Multiply the product you get in step 1 for the last number:
Then, the product of 0.42, 1.5 and 2.33 is 1.46790
