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☝️ Counting One by One

Touch each object exactly once as you count — no skipping, no double-counting. It's the golden rule that makes every count come out right.

lessons

~15 min

to learn

🔢 Math

subject

Ages 6–12

level

Start the course →

What you’ll learn

One Touch, One NumberCount with one-to-one correspondence — one number for each object.The golden rule of counting is one touch, one number. Point to each object as you say a number, giving each exactly one. This one-to-one matching is what makes a count accurate.
Don't Skip, Don't RepeatAvoid skipping objects or double-counting when counting a set.Skipping an object makes the count too small, and counting one twice makes it too big. Counting slowly, saying numbers aloud, and moving each object aside keep every object counted exactly once.
Counting CarefullyCount a set carefully, using strategies like moving counted objects aside.To count carefully, touch each object once and, for a pile, slide each into a 'counted' group as you go. This keeps counted and uncounted objects separate, and the last number tells how many.

Questions this course answers

When you count, how many numbers do you say for each object?

One number for each object — the golden rule.

If you skip an object while counting, your number will be:

Skipping means you counted too few, so it's too small.

Counting the same object twice makes your number:

Double-counting adds an extra, so it's too big.

A good trick to not lose track when counting a pile is to:

Setting counted objects aside keeps them separate.

Grounded in trusted sources

Khan Academy Kids
PBS Kids — early math
NAEYC — early math learning
Britannica Kids

Every Wunder lesson is built from real, reputable sources — never invented.

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