## Ten Pins

### Kathy Pajak

#### Description

Students use computer-based and hands-on activities to discover and explore patterns of multiplication using multiples of 10, 100, and 1,000.

#### Objectives

The student understands and applies basic number theory concepts, including primes, composites, factors, and multiples.

#### Materials

-Internet accessible computers
-Practice pages exploring multiples of 10, 100 and 1,000 (teacher-generated worksheets or samples from classroom textbook series)
-Grab bags (for clothes pins)
-Clothes pins with multiplication problems and answers (see procedures)
-Clothesline

#### Preparations

1. Write multiplication problems for multiples of 10, 100 and 1,000 on the outside of the clothes pin.
2. Write the answer to the multiplication problems on the inside of the clothes pin.
3. Put the clothes pins in grab bags.
4. Hang the clothesline at an appropriate height for students to reach to hang clothes pins.
5. Set up the activity center with grab bags full of clothes pins.
6. Turn on computers and bookmark the Student Web Lesson, Hotel 6.

#### Procedures

Whole Group activity

1. Introduce multiplying with multiples of 10, 100 and 1,000 by showing a pattern with zeros.

Example:
5 x 1 = 5
5 x 10 = 50
5 x 100 = 500
5 x 1,000 = 5,000

Example:
6 x 7 = 42
6 x 70 = 420
6 x 700 = 4,200
6 x 7,000 = 42,000

2. The class thinks about and discusses these patterns with zeros.

* The number of zeros in both factors equals the number of zeros in the product.

3. Students use these patterns with zeros to solve additional problems on the board or overhead.

4. During a whole class discussion, students describe the pattern for multiplying by multiples of ten.

5. Divide students into three rotating groups.

Group 1:
Complete practice pages exploring multiples of 10, 100, and 1,000 at desks. (If students finish early, have them turn their papers over and create problems for a partner to solve.) Students should keep their practice pages at their desks until after the Wrap-Up session.

Group 2:
Complete the Student Web Lesson, Hotel 6, at the computer workstations. (See Weblinks)

Group 3:
Complete the TenPins activity at an activity center.

The TenPins activity is described below:

a. Students choose a partner. Each set of partners receives one grab bag full of clothes pins.

b. Partner #1 draws one wooden clothes pin out of a grab bag.

c. Partner #1 reads the multiples of ten multiplication fact found on the outside of the clothes pin and then hands the clothes pin to Partner #2.

d. Partner #1 answers the multiplication problem.

e. Partner #2 opens the clothes pin to check the answer. If the answer is correct, Partner #1 hangs the clothes pin on the line and chooses another clothes pin out of the grab bag. Partner #1 continues until he gives an incorrect answer. Partner #1 returns this clothes pin back to the grab bag.

f. Partner #2 then chooses a clothes pin out of the grab bag and begins the cycle again. Continue this until all the clothes pins are out of the grab bag and on the line.

Wrap-Up:

7. When all rotations have been completed, the students come back together and discuss what they have learned about multiplying multiples of 10, 100 and 1,000. The teacher asks questions to guide the discussion. For example, the teacher may ask a student to multiply 8 x 1. The student should answer 8. The teacher may then ask another student to multiply 8 x 10. The student should respond 80. The teacher asks a third student to multiply 8 x 100. The student should respond 800.

8. Students continue discussing how to multiply using multiples of 10, 100 and 1,000 by giving examples. The teacher writes a few problems on the board. Each student works these problems individually. The students and teacher check and correct these problems together. This way the teacher knows immediately which students do not comprehend how to multiply by 10, 100 and 1,000, and can provide additional instruction as needed.

9. Before students turn in the practice page from Group 1 to be assessed, allow them time to review their work and answers and make corrections in light of the wrap-up practice and discussion.

#### Assessments

The student practice pages are used to assess whether or not students can solve problems using a predictable numerical pattern as they multiply by 10, 100 and 1,000. Problem answers are assessed based on a percentage of the number of items correct.