Activity with Number lines (Primary 2)

OBJECTIVE: To apply the concept of a line as a visual picture of addition and subtraction and more than and less than.

MATERIALS: A laminated number line for each child, a large laminated number line that can be used for demonstration and/or a permanent number line on the chalkboard, markers (i.e., chips) to mark places on the number lines.

ACTIVITIES: The number line can be used to illustrate the following:

1. Greater and less than.  PUT A MARKER ON THE 4.   FIND A NUMBER THAT IS GREATER THAN 4.  PUT A MARKER ON IT.  Discuss which numbers were selected.  How did they know which numbers were greater than 4?  Go through the same procedure with the other numbers.  Then go through the procedure looking for numbers less than a given number.
2. Addition.  HOW CAN WE SHOW 2 + 4 ON THE NUMBER LINE?  Encourage the children to try to figure it out.  If they can't, then demonstrate.  FIRST I'LL PUT A MARKER ON 2.  Have the children try several problems with sums of 10 or less.
3. Subtraction.  HOW CAN WE SHOW 5 - 2 ON THE NUMBER LINE?  Encourage the children to try to figure it out.  If they cannot, then demonstrate.  FIRST I'LL PUT A MARKER ON THE 5.  NOW WHICH WAY SHOULD I GO TO FIND 5 - 2?  Have them try several problems using numbers 10 or less.

FOLLOW-UP: Have the children illustrate equivalent sums and differences on the number line (i.e., 3 + 4 = 1 + 6; 8 - 4 = 7 - 3).  The children could also make up number line problems for themselves.  Suggest that when they need help with a one-digit problem, they use the number line to find the answer.

Charlesworth , Rosalind.  Experiences in young children (1996).  Albany, NY: Delmar