Step 1: Complete the multiplication as you normally would, as if the decimals were not there.
Step 2: Determine the total number of digits after the decimal points in the numbers you're multiplying together.
Step 3: Place the same number of digits behind the decimal point in the product.
1.56+2.47
You can take out the decimal point
156+247=403
Then add the numbers
Add the decimal point back
4.03
Done