Odd/Even, Skip Counting & Number Patterns
Skip-count by 2s, 5s, and 10s, master odd and even, and crack any pattern rule.
1 Skip-counting: jumps of the same size
Skip-counting jumps forward by 2s, 5s, or 10s. Watch the ones digit: it flips 0, 5, 0, 5 for 5s, and never changes for 10s.
5, 10, 15, 20 — add 5 each time.
34, 44, 54, 64 — only the tens digit changes.
2 Odd and even: can it pair up?
An even number splits into two equal groups with nothing left over. An odd number always has one left over. Just check the ones digit: 0, 2, 4, 6, 8 are even.
37 ends in 7, so it is odd — one is always left over.
0 splits into 0 and 0 with nothing left over, so 0 is even.
3 Find the rule, extend the pattern
Subtract neighbors to find the rule. If every jump is the same, extend it: 7, 11, 15 → rule +4 → 19.
11 − 7 = 4, 15 − 11 = 4, so the rule is +4: 15 + 4 = 19.
37 − 40 = −3: the rule is −3, so 34 − 3 = 31.
4 Common mistakes
Two pattern traps.
Wrong: “0 is odd because it is nothing.” Right: 0 pairs up perfectly (0 and 0) — it is even.
Wrong: 95, 100, 110, 115 … (the 105 vanished). Right: watch the ones-digit pattern (0, 5, 0, 5) or use a hundreds chart.
5 Quick checks
Try these yourself, then reveal the answer.
6 Key points and vocabulary
| Word | What it means |
|---|---|
| Skip-count | Counting by jumps of 2, 5, 10, … |
| Even | Splits into two equal groups; ones digit 0, 2, 4, 6, 8. |
| Odd | One left over after pairing; ones digit 1, 3, 5, 7, 9. |
| Pattern rule | What happens each step, like “add 4”. |
| Term | One number in the pattern. |
Remember
- Skip-count by watching the ones-digit pattern.
- Even pairs up; 0 is even.
- Find the rule by subtracting neighbors.
- Past 100, trust the digit pattern — not your memory.