Spanish to English Science Mathematics & Statistics

This is a math textbook. The last sentence is written in Klingon to ensure all of the students have no idea what it says. There is no further clarification. My problem here is knowing what they are talking about so I can hammer it into something that everyone will have no choice but to understand clearly. Impossible to misunderstand is the goal.
Cheers!

Here is a website with exactly the same text.

https://personal.us.es/cmaza/docencia/repasomates.pdf

ORIGINAL
Para multiplicar números decimales, se colocan unos debajo de otros. Se multiplican
como si fueran números naturales. En el resultado, se separan desde la derecha con
una coma un número de cifras decimales igual a la suma de las que tienen los dos
factores. Si no hubiera bastantes cifras para separar los decimales, se ponen los ceros
que sean necesarios delante de las cifras significativas.

ROUGHT DRAFT
To multiply a decimal number by another decimal number starting with a zero, write the result, and starting from the left move the decimal point right a number of positions equal to the number of digits to the right of the decimal points in the factors. If there are not enough digits, put as many zeros to the left as necessary.