Chapter 5.2, Problem 3P

Leah is working on the multiplication problem $2.43\times \mathrm{0.148.}$ Ignoring the decimal points, Leah multiplies $2.43\times 148$ and gets the answer 35964. But Leah can’t remember the rule about where to put the decimal point in this answer to get the correct answer to $2.43\times \mathrm{0.148.}$ Explain how Leah can use reasoning about the sizes of the numbers to determine where to put the decimal point.