People in Line - Ordinal numbers, Counting back, Counting forward.

On the Number Line - Ordering numbers.

Problem:  There are 11 people in line.  You are in the middle of the line.  What number tells your position?

Math Topic/Concept: Ordinal numbers, Counting back, Counting forward.

Materials:  Various

Classroom Use: Introductory/Developmental

Classroom use comments*: The solution to the problem can be found easier if manipulatives are used.

Grade:  1

Grade Cluster: Early Elementary

Illinois Goal:  6 and 10

Standard:  6 A 1a and 10 A 1a

Applied? (1-4):  Level 3

Source: Houghton Mifflin Mathematics, First Grade, Problem of the Day, Chapter 5, Lesson 16, 2001

Answer:  6

Strategies Listed: Counting back, counting forward, Use manipulatives, order

Solution: The student will make a train of 11 blocks.  S/he will need to determine the middle block by using one to one correspondence counting forward or backward.

Other solution methods (if any)*:  A number line may also take the place of the blocks in the previous solution.

Extensions or related problems*: Have the students line up and act out the problem.

Write-up submitted by:  Cyndi Fisher and Jodi Johnson

Problem:  Carlos and Jamie played a game called “About Where Does It Go?”  One person said a number between 0 and 1,000 and the other person showed where the  number would go on the number line.

Try the game.  Place each of the numbers below on the number line by making a mark where you think it belongs.  Then, above the mark, write the letter that is in front of the number.  Explain how you decided where to place each number.

A.  450  B.  700  C.  100  D.  850

Math Topic/Concept:  Ordering numbers.

Materials:  paper and pencil

Classroom Use: (Introductory/Developmental)

Grade:  3

Grade Cluster: (EarlyElem)

Illinois Goal:  6

Standard: 6.A.1

Applied? (1-4): 1

Source:  Explain It, Grade 3, Creative Publications, 2001

Answer:  See solution.

Strategies Listed: Make a diagram

Solution:  Students should explain that 500 is halfway between 0 and 1,000 so it should be in the center of the number line.  Numbers 100 and 450 would be to the left of the midpoint because they are less than 500; 100 should be closest to zero and 450 should be closer to the center of the line.  Both 700 and 850 should be to the right of the center of the number line: 700 should be closer to 500, or the midpoint, and 850 should be closer to 1,000.

Intended rubric or assessment method:  Informal assessment.

Write-up submitted by:  Diana Kent
 
 

James R. Olsen, Western Illinois University
E-mail: jr-olsen@wiu.edu
updated Aug. 20, 2001