Teaching Decimals
Rounding Mixed Decimals to the Nearest Tenth
A concept in mathematics that students need to learn in elementary school is to round mixed decimals to the nearest tenth. This essay describes how I would teach this concept to a group of fourth grade students.
To begin, I would identify the prerequisite skills that students need in order to master this concept. First the students need to understand place value of whole numbers and decimals; this is necessary because rounding can affect the amount in a specified value. Another prerequisite is that students need is to be able to round whole numbers; if students do not know when to round to ten or zero, they will not be able to accurately round decimals. Finally, a concept that relates to place value that students need to know is what decimals represent. Students need to understand that decimals are a portion, or fraction, of a whole and are located to the right of the decimal point, while whole numbers are located to the left. Additionally, for the activities in this lesson, the students need to be familiar with adding money and adding decimals of the tenth degree.
Once I know that the students have these prerequisite skills, I would begin instructing on the concept of rounding to the nearest tenth. I would begin by giving the students a number containing a decimal to the hundredths place, such as 0.17. I would then have them circle the tenths place as a visual reminder of the place value to which we are rounding. I would then ask the students at what point we round up or down with whole numbers; the correct response should be to the effect of “a number less than five means to round toward zero and a number more than five means to round up.” I would inform the students that this also applies to decimals, and when rounding to the tenths place, the number in the hundredths place is the determining factor of rounding up or not. Since the number is 0.17, the number then becomes 0.2 because the place value
A concept in mathematics that students need to learn in elementary school is to round mixed decimals to the nearest tenth. This essay describes how I would teach this concept to a group of fourth grade students.
To begin, I would identify the prerequisite skills that students need in order to master this concept. First the students need to understand place value of whole numbers and decimals; this is necessary because rounding can affect the amount in a specified value. Another prerequisite is that students need is to be able to round whole numbers; if students do not know when to round to ten or zero, they will not be able to accurately round decimals. Finally, a concept that relates to place value that students need to know is what decimals represent. Students need to understand that decimals are a portion, or fraction, of a whole and are located to the right of the decimal point, while whole numbers are located to the left. Additionally, for the activities in this lesson, the students need to be familiar with adding money and adding decimals of the tenth degree.
Once I know that the students have these prerequisite skills, I would begin instructing on the concept of rounding to the nearest tenth. I would begin by giving the students a number containing a decimal to the hundredths place, such as 0.17. I would then have them circle the tenths place as a visual reminder of the place value to which we are rounding. I would then ask the students at what point we round up or down with whole numbers; the correct response should be to the effect of “a number less than five means to round toward zero and a number more than five means to round up.” I would inform the students that this also applies to decimals, and when rounding to the tenths place, the number in the hundredths place is the determining factor of rounding up or not. Since the number is 0.17, the number then becomes 0.2 because the place value