Lesson 1

Group and Count by Fives and Tens

Est. Class Sessions: 2–3

Developing the Lesson

Part 2: Group and Count Connecting Links

Count 24 Links. Show students a chain made of 24 links that does not have the colors organized in any way.

Ask:

X
  • How can we use the ways we counted pennies, dimes, and nickels to find out how many links are in this chain? (Count the links in groups by twos, fives, or tens.)

Tell students that they are going to measure objects in the room using chains made of links. Demonstrate measuring your desk or another object with the chain. Begin counting by ones.

Ask:

X
  • Is there an easier, more efficient way to count the links? (Possible response: Count by fives [twos or tens].)
  • How can I organize my links so that it is easy for me to count by fives [twos or tens]? (Make five links yellow, five links blue, five links yellow, etc.)
  • If I make my chain with alternating colors, could I have leftovers? If so, how will I count them? (Yes, there might be leftovers. Count the leftovers by ones.)

Distribute a two-color collection of about 50 individual links to each student pair. Have students set 24 aside.

Ask:

X
  • Think about how you can build a chain that is 24 links so that it is easy to count the links. What will you do?

Discuss students' strategies. Some students may choose to organize their chains by twos. Others may choose to count by fives or tens. As groups choose ways to organize their chains, make sure that there will be at least two chains organized in twos, another two chains in fives, and two chains in tens in the class. Remind students that they might have leftovers that they will count by ones.

When students have completed their chains, ask groups to come to the front of the class and count their chains, skip counting by the appropriate number and counting the leftovers by ones. As each group finishes counting, pin the chains to a bulletin board so that they hang vertically and students can compare the lengths. See Figure 2.

Ask:

X
  • How are all the chains alike? (They are all the same length. They all have 24 links. They all have two colors that alternate.)
  • How do you know they all have 24 links? (We counted the links in our chain and it has 24 links. All the other chains are the same length.)
  • How are the chains different? (They have different colors. Some are made to count by fives, some by twos, and some by tens.)
  • Which is the most efficient way to count?
Adventure Book:
Student Activity Book:
Master:
Hanging chains to compare lengths
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