I need help with decimals 2.1 x 5.01?

Answer 1

A simple trick with multiplying decimal numbers is to remove the decimals, multiply the two numbers, then add the decimals back in. The number of decimals you add back in is the total number of decimal places.

For example, the stated problem has 1 decimal places in 2.1 and 2 decimal places in 5.01. So first we do the following:

21x501=10521

Now we add 1+2=3 decimal places into the result above:

10.521

That's the answer.