Math Background

Lesson: Modeling and Recording Addition
Introducing the Concept

Children first learn the concept of addition by adding 1 more to numbers from zero to 9. At the Kindergarten level they will model addition by counting on and recording the number of items in all.

Materials: overhead projector, counters, number cards for the numbers 1-10 and the plus sign and equals sign

Preparation: Prepare number cards for 1-10 and plus and equals. You can use Learning Tools 8 and 9 in the Learning Tools Folder.

Prerequisite Skills and Concepts: Children should be proficient in counting and recognizing numbers to ten.

  • Say: I would like volunteers to help me act out a story.
    Have two children come up to the front of the classroom.
  • Ask: How many children are at the front of the room?
    Children should say “2.”
  • Say: Two people are at the front of the room.
    Ask another child to come to the front of the room.
  • Say: Now one more person is at the front of the room. Let's count how many people are at the front of the room now.
    Have the children count aloud to 3.
  • Ask: What did we do when we asked another person to come to the front of the room? (We increased the group by one.)
    Continue adding one more child and counting the new number until five children are at the front of the room.
  • Ask: What did we do each time?
    Children should say that we added one more to the group.
  • Ask: What happened to the number of children each time we added one more to the group?
    (The group had 1 more each time.)
  • Say: Now let's do this with counters.
    Direct the children to look at the overhead.
  • Ask: How many counters are on the overhead?
    Children should say “zero.” Place one counter on the overhead.
  • Ask: If I add one counter, what is the total number of counters? (1)
    Place the 1 number card where the children can see it. Repeat, adding one more until you have placed the number cards for 1 to 5 in a line.
  • Ask: Do you see a pattern?
    Children should see that when you add one to a number, you get the number after it.
    Add the cards for 6 to 10 to the line.
  • Ask: If I add one to seven, how many will I have?
    Children should say “eight.”
  • Say: Seven plus one equals eight.
    Point to the appropriate number cards as you say this. Continue using the number cards to add 1 to numbers up to 9.
  • Say: Now let's learn how to write addition sentences.
    Put four counters up on the overhead.
  • Ask: How many counters do I have?
    Children should say “4.” Write 4 on the overhead.
  • Say: Now let's add one more.
    Place one more counter and write 1 on the overhead.
  • Ask: What is the total number of counters?
    Children should say “5.” Write 5 on the overhead.
  • Say: We can show how we added 1 more to 4 and got a total of 5 by using math symbols.
    Write a plus sign between the 4 and the 1.
  • Say: This is a plus sign. It tells us that we are adding. Can you make a plus sign with your fingers?
    Model making a plus sign with your fingers. Then write the equals sign on the overhead.
  • Say: This is an equals sign. It tells us that the amounts on either side are the same.
    Continue as above, modeling different addition sentences with counters and recording them on the overhead. You may wish to have students volunteer to hold the number cards and the symbol cards that represent what you are adding on the overhead.

Houghton Mifflin Math Grade K