Skip Counting by 2s, 5s, 10s

Arithmetic · Axiom Academy

LESSON Skip Counting by 2s, 5s, 10s Counting in equal steps — a faster way to count, and the foundation of multiplication. Counting by 2s means each count adds 2 to the previous one. You say every second number and skip the rest — useful for anything that comes in pairs. Counting by 5s takes bigger steps: each count adds 5. Ten steps already reach 50, and the sequence falls into a strict pattern. Nickels are worth 5 cents each, so counting a stack of nickels is counting by 5s: 5, 10, 15, 20 cents. A clock face works the same way — each minute mark stands for 5 minutes. Counting by 10s is the fastest of the three: each step is a full group of ten, so only the tens digit changes. Dimes are worth 10 cents each: 6 dimes is 10, 20, 30, 40, 50, 60 cents. Inventory counted in boxes of ten works the same way. The same numbers light up on a hundred grid below — see the rhythm of every 2nd, 5th, and 10th cell. Then fill in the missing numbers in each sequence, using the last-digit patterns to check your work. Skip counting is more than a counting shortcut — it is repeated addition, which is exactly what multiplication measures. Skip counting moves forward in equal steps: by 2s, 5s, 10s, or any fixed amount. By 2s the counts end in 0, 2, 4, 6, 8 — the even numbers. By 5s the counts end in 5 or 0; by 10s they end in 0. Counting n steps of size k lands on n × k — skip counting is multiplication in motion.

This is the written version of the interactive lesson above. See the full Arithmetic course.