To multiply a whole number by a fraction less than one, you have to rewrite the whole number in the expression as a fraction by putting a one under it. For example, in 10 x 2/5, you would rewrite the 10 to 10/1 x 2/5. Then, you would multiply the top and bottom of the two fractions. In this case, it would be 10 x 2 and 1x5. This would result in 20/5. Finally, you would simplify this fraction by dividing. The final answer is 4.
When you are multiplying a whole (big) number times a fraction, you multiply the whole (big) number times the TOP number (numerator) and put that on top. Keep the bottom number (denominator) the same.
