Comparing Groups to 20
Students will be able to write and compare numbers 11–20.
- Gather the class together for a read-aloud.
- Display Mimi's Book of CountingAnd ask the students how to count to 10. Have them count aloud with you.
- Read the book aloud. As you read, ask guiding questions such as: "What do you see on this page?" "How many ________Are there?" "Can you count along with me?"
Explicit Instruction/Teacher modeling(5 minutes)
- Display two groups of objects (e.g., 4 buttons and 7 bears) and ask students to think about which group has more objects. Have students turn and talk to share their ideas with a partner (e.g., which looks like more, counting each group, etc.)
- Model counting each group (using a number line for support) and identifying the number in each group, writing the numbers down on the board, and comparing each group to see which has more.
- Explain that to CompareMeans to find out how they are different or the same--in this case, which group has more and which group has less.
Guided practise(5 minutes)
- Tell the class that now they will get to play a game of Count and Compare with a partner.
- Go over the instructions and model how to play the game using a student as your partner:
- Count the objects in your bag. Recount the objects using the number line to double-check your work.
- Colour in the circles on the worksheet to show how many objects are in your group.
- Share the number of objects in your group with a partner. Then trace the matching number on the worksheet in the same colour (e.g., blue).
- Record your partner's objects by coloring in the matching number of circles in a different colour. Then trace the matching number on the worksheet in the same colour (e.g., yellow).
- Decide if you or your partner has more or less and fill in the bottom of the worksheet.
- Review any partnership expectations.
Independent working time(15 minutes)
- Pair students together for the activity.
- Pass out a bag of objects and a number line to each student. As students work, ask guiding questions such as, "How many objects are in your bag? How do you know for sure?" Encourage students to practise recounting each group to check for accuracy.
- Pass out individual number lines or hundreds charts to each group. Have students work in a small group to practise additional counting activities with more support (e.g., singinng counting songs, counting objects, playing a counting game, etc.).
- Practise counting larger numbers of objects. Teach students how to idenify and use comparison symbols when comparing groups of objects.
- As students work, circulate around the room as ask guiding questions such as: "How many objects do you have? How do you know? Can you use the number line to show me?"
- Check to see if students are able to accurately count without missing numbers. Can they record the matching number of objects? Are they able to determine which group has less and which has more?
Review and closing(5 minutes)
- Review the lesson's big ideas (counting to 20, comparing objects) by playing a quick game with the students:
- Have two uneven groups of 10 or fewer students come to the front of the room (separate the groups). Count each group (with the help of the class) to determine which is less and which is more.