Skip Counting by Twos
Students will be able to skip count by twos and understand when it is appropriate to skip count by two.
Introduction (10 minutes)
- Introduce the lesson with a warm-up question.
- Tell students that the principal is taking a poll to find out how many students are in the first grade. She needs to know how many students are in our class.
- Ask someone to volunteer to count the number of students in the classroom.
- A student is most likely to count by ones to accomplish this task. Ask her if she knows of a faster way to count than by ones. If the students do not say “counting by twos,” then suggest that you try counting by twos as a class.
- Once you have counted by twos as a group, ask the students which method was faster: counting by ones or by twos.
- Ask students to name other situations in which they have heard people counting by twos. For example, have they heard people counting by twos during class field trips?
- Explain that students can count by twos in their own lives as well, e.g. when they are counting how many coins or how many toys they have.
Explicit Instruction/Teacher Modeling (10 minutes)
- Show a hundreds chart to the class that has every other square filled in with a number.
- Explain that the every other square is filled in because we are counting by twos. Mention that this is also known as skip counting.
- Take two counting bears at a time and count as you start writing in the multiples of two. For example, take two green ones and put them on the table saying "two," then two red ones saying "four," then two blue ones saying "six."
- Tell the students that they can use the counting bears if they need help when they try on their own, but to try to take two of the same color of each bear each time they put them down. This way, if they get lost in the counting, they can count by ones to find the number they were at and visually see the pairs of two represented.
Guided Practice/Interactive Modeling (5 minutes)
- Ask the class to count together as you finish writing or circling the multiples of two in the chart through the number 20.
- Ask students to practice counting by twos aloud with you, starting with the number two. Go up to 20 so that they can get an example of what they will be doing with their own charts.
- Point to each number on your chart as you count.
Independent Working Time (15 minutes)
- Explain to the students that they are going to practice filling in their own hundreds charts by counting by twos so that it looks like the sample one that you have made.
- Ask the students to take their hundreds chart and try to fill in their charts, starting with the number two and counting by twos. (If the hundreds chart worksheet is blank, the students should write in the numbers themselves. If the hundreds chart is filled in, the students should start at the number two and circle each number as they count by twos).
- Walk around the room and help any students who are struggling.
- When the students have finished, ask them to review their charts with a partner to see whether their charts look the same. If there are differences, ask them to talk to their partner and try to agree on what numbers should be filled in.
- Ask students questions to help them grasp the concept as you walk around checking their work. For example: Why did your partner fill in a different number than you? How can you go back to a number that you know is right and go from there to find the next number?
- Enrichment: If students demonstrate mastery or fill in their charts quickly, you can let those students form a group at a station in pairs. You can give them each a new hundreds chart and ask them to have a partner time how long it takes for them to fill out the hundreds chart by themselves without any counting bears.
- Support: Encourage struggling students to use the counting bears to figure out what number comes next in the line. If they still struggle, you can give them a blank hundreds chart and let them count by ones first to fill out each space. Then ask them to highlight every other space starting with the number two, saying each number aloud as they go.
Assessment (10 minutes)
- Review each student's chart and evaluate whether the multiples of twos were correctly identified.
- Ask students to look at their charts and write about any patterns they noticed in their charts.
- Give an exit slip to each student and ask everyone to circle the number that explains how they feel about counting by twos, with 1 being sad and 5 being happy. This will give you a sense of how much more work needs to be done on counting by twos.
Review and Closing (10 minutes)
- Ask the students to explain why we sometimes count by twos.
- Ask students to give an example of when we might want to count by twos, such as when we are trying to count to a larger number like 50. If we are only counting to a small number like 4, we don't need to skip count by twos.
- Ask students whether they think it is possible to skip count by higher numbers, such as 5 or 10.