CPM Homework Banner

Mentally calculate the following products. Use the rule for decimal multiplication to write an equation in which the decimal point is written in the correct location.  

Compute without a calculator


    Think: A small number times a small number is a ____ number.

    A negative number times a negative number is a _____ number.

    Multiply and move the decimal three places to the left.



    See part (a).

  1. Stacey said, “Stephanie, look at my answer to the last problem, . Usually when I multiply, I get a bigger answer than the numbers I start with. Twenty-eight hundredths, , is less than either or . I must have made a mistake.”

    Stephanie responded, “Well, one half times one half is one fourth, and one fourth is less then one half. I think when you multiply by a fraction or decimal less than one, you get less than you started with.”

    Write a sentence or two about who you think is correct and why.

    Stephanie is correct. Why?