Lesson 28: Skip Counting by 2s and 5s
Lesson Objectives
- Skip count up and down by 2 and 5’s using concrete objects and pictures
- Skip count up and down by 2 and 5’s using numbers, number lines, and hundred charts
- Skip count using patterns
- Use arrays as a strategy for skip counting
Materials
- Extend Workbook (Page 28)
- Counters or manipulatives
- Various number lines (100s Chart, 0-50)
- Highlighters, markers, or crayons
- TouchMath’s number line
Step 1: Warm Up (5 min)
Then, use a number line 0-20. Review skip counting by 2’s. Then, start on the 5’s and skip every other number (5,10,12,14) until you get to 50. Have them look at the sequence and point out that when skip counting on 5’s, that the first two 5’s make 10, and in other words means 5+5. Explain that skip counting is adding multiple addends – the same addend over and over. It is easier to skip count than to add all of the addends when we get to larger numbers. Explain that this also means we are adding groups of the same number of items together.
Step 2: Vocab Review (5 min)
Introduce repeated addition and skip counting, and review even numbers. Skip counting is a tool that will help us find pairs of equal addends. It is also the foundation of multiplication. Tell students that they will be learning a process that will make it very easy for them to learn how to multiply. Remind them that they can count forward and backward, but that they can also skip numbers in sequence. When we skip count, we start on a number and skip every other number in sequence. Remind them of even numbers: Even numbers always have two equal addends. For example, 8 has two equal addends, 4 + 4. The number 20 has two equal addends, 10 + 10. We will find ways to identify the two equal addends for even numbers.
Step 3: Model (5 min)
Find a skip counting song (by 2 and 5) and remind students about the importance of skip counting. See if any students can skip count by 2’s or 5’s already. Ask students to skip count backwards, after practicing forward (using number lines, as needed). Then, practice skip counting: take counters and divide 10 into two equal sections. Ask students to tell you how many counters are in each group (5) and then ask how many groups are there total (2). Tell students that this is the same thing as 5+5, which equals 10 total counters. Show several examples skip counting using counters or manipulatives, skip counting forward and backwards.
Step 4: Guided Practice (5 min)
Distribute a 100s chart, and start on 2. Ask students to skip count by 2’s forward to 60. Have them circle each number with a red marker. Then, ask them to skip count by 2’s backwards until they get to 0. Have them circle each number with a yellow marker to see the difference between skip counting forward, and skip counting backward. Ask students to write down multiples of 2 from their 100s Chart up to 60 on a separate sheet of paper.. Distribute another 100s chart, and start on 5. Ask students to skip count by 5’s forward to 50. Have them circle each number with a red marker. Then, ask them to skip count backwards until they get to 0. Have them circle each number with a yellow marker to see the difference between skip counting forward, and skip counting backward. Ask students to write down multiples of 5 from their 100s Chart up to 50 on a separate sheet of paper.
Step 5: Student Practice (5 min)
Go to Student Workbook Page (27). Read the directions at the top of the page. Tell students they will be practicing skip counting forward and backward by 2’s and 5’s starting on different numbers. Remind students that they can use their 100s chart or multiples of 2 or 5 resource page that they created on the guided practice. Looking at the first sequence, ask students to skip count by 2’s from 40 within each box to the right of the 40 to complete the pattern. Finish the next 3 sequences, following the directions to skip forward or backward based on the directions.
Step 6: Wrap Up (5 min)
To wrap up the lesson, review the learning objectives and core vocabulary words again and ask your students about their experience.
