Skip-Counting and Number Patterns
Warm-up
Count with me by 2s! Whole class: 2, 4, 6, 8 ... 20. Do it with movements: clap on each number, stomp on every 10th. What patterns did we find? When did everyone stomp?
Explore
Students colour multiples of 2 in yellow on their hundred chart, then multiples of 5 in blue. Ask: What do you notice? Are any squares both yellow and blue? What does that mean? The overlap squares (multiples of 10) generate rich discussion.
Formalize
Debrief the pattern. Yellow squares all end in 0, 2, 4, 6, or 8: those are even numbers. Blue squares end in 0 or 5. Both-colour squares end in 0: multiples of 10. These patterns are genuine number theory emerging from exploration.
Skip-Counting and Number Patterns
Connect to equal groups: place 3 groups of 2 linking cubes. How many altogether? Count by 2s: 2, 4, 6. We counted 3 groups of 2 and got 6. Skip-counting is the same as adding the same number over and over.
Practice
Students complete a hundred chart colouring activity (multiples of 10 in red) then describe the pattern in words. Exit ticket: count by 5s starting from 15. Write the next 5 numbers.
Exit ticket
Students complete a hundred chart colouring activity (multiples of 10 in red) then describe the pattern in words. Exit ticket: count by 5s starting from 15. Write the next 5 numbers.
Step 1: Build the count, don't just chant it: snap cubes into towers of 5. Lay down one tower: 5. Another: 10. Another: 15, 20, 25.
Step 2: Ask the money question: "When we say 5, 10, 15 — what are we actually counting?" (Towers. Groups. Handfuls of five.) Each number word names a whole GROUP landing, not a single object.
Step 3: Check for real understanding: cover the towers and ask, "We said 20. How many towers are hiding?" A student who knows 20 means four fives has it; a student who only memorized the chant can't answer.
Step 4: Connect to the 100 chart: colour the count — 5, 10, 15, 20… The two stripes down the chart (the 5s column and the 10s column) make the pattern visible: every skip-count lands in the same two columns forever.
The count: 3, 5, 7, 9, 11…
Step 1: A student objects: "That's wrong — skip-counting by 2s goes 2, 4, 6, 8!" This is the moment to separate the JUMP SIZE from the STARTING POINT.
Step 2: Show it on a number line: start your finger at 3 and make jumps of exactly 2. The jumps are identical to the 2, 4, 6, 8 jumps — only the launch pad moved.
Step 3: Name what you get: starting at an odd number and jumping by 2 lands on ALL the odd numbers; starting even lands on all the evens. The class has just discovered that the numbers split into two interlocking families.
Step 4: Extend: "Will 24 ever appear if we keep going 3, 5, 7…? How do you know?" (Never — 24 is in the other family.) That's a prediction from structure, not from counting all the way up.
Step 1: Make a table together — position on top, number underneath: position 1 → 4, position 2 → 8, position 3 → 12.
Step 2: Hunt the relationship DOWN the table, not just along the list: position 2 gives 8, which is 2 fours. Position 3 gives 12 — three fours. Each position holds that-many fours.
Step 3: Jump straight to position 10: ten fours. Count by 4s ten times if needed — 40 — or use the doubling shortcut: position 5 is 20, and position 10 must be double that.
Step 4: Say the general rule in Grade-1 words: "the number is always 4 groups of the position number." That sentence IS multiplicative thinking, a full year before multiplication is taught.