In our school, we are adding and subtracting decimal fractions. We used pieces of Creme de la Crumb (cut from paper) from our story a couple of weeks ago to demonstrate regrouping or borrowing and carrying, tenths and hundredths. Because adding and subtracting decimal fractions is so similar to adding and subtracting whole numbers, the students felt confident doing this.
We extended our addition and subtraction to money and discussed that a penny is one-hundredth of a dollar, a nickel is five-hundredths of a dollar, a dime is 10 hundredths or one-tenth of a dollar, and a quarter is 25 hundredths of a dollar.
Later in the week, we moved on to multiplication. We studied the problems as a fraction, a decimal fraction, and by shading an area model. Looking at all three representations together helped us understand what happens when we multiply decimal fractions. This is also a way to verify our answers and connect the models. We will continue to practice multiplying decimal fractions throughout the next few weeks.
While multiplying decimal fractions, we also practiced with the shortcut when multiplying by multiples of tens. It is so handy to just move the decimal point! We will look at how to do that with division next week!