Teaching the Common Core Math Standards With Hands-On Activities, Grades 3-5 (60 page)

Once students know how to multiply and divide a number by powers of ten, they can find patterns in the number of zeros and placement of a decimal point. When multiplying by a number that is a power of 10, students must move the decimal point to the right as many places as the exponent. For example,
The decimal point, which is understood to be to the right of 3, is moved two places to the right because the exponent is 2. If the number is written without an exponent, such as 100, the decimal point is moved to the right as many places as there are zeros in the number. For example,
The decimal point is moved two places to the right of 3 because 100 has two zeros. When dividing by powers of 10, students must move the decimal point to the left as many places as the exponent. For example,
If the number is written without an exponent, such as 100, students must move the decimal point to the left as many places as there are zeros in the number. For example,

Activity: Charting Patterns in Powers of 10

Working in groups, students will create posters that explain and show patterns in multiplying and dividing powers of 10.

Materials

Scissors; glue sticks; markers; crayons; rulers; poster paper; various colors of construction paper for each group.

Procedure

1.
Review place value with your students and especially note the powers of 10 that each place represents. Also note the number of zeros in each power. For example,
and

2.
Explain that students are to create posters that are based on place value and that show patterns in the placement of the decimal point when multiplying or dividing by powers of 10.

3.
Suggest that students brainstorm ideas before beginning work on their posters. What important ideas do they want to include on their posters? What is the best design for their posters? What examples might they include to illustrate their ideas?

4.
Offer some examples of numbers that students might use to identify patterns in the placement of the decimal point when multiplying or dividing by powers of 10, such as:
and
and
and