count by twos

In older textbooks, this technique is called counting by twos (threes, fours, etc.).

In skip counting by twos, a person can count to 10 by only naming every other number: 2, 4, 6, 8, 10.

The series focuses on the eponymous growing young turtle who, as his television stories and books always begin, "could count by twos and tie his shoes".

She reminded the boys and girls what they had learned last year, about how to count by twos, and she told them such numbers were called multiples of two.

A 2008 draft mathematics standard proposed that Kindergartners multiply to 30 by skip counting (also known as counting by twos: 2, 4, 6, 8...), and that second graders solve simple algebra story problems.

Counting sometimes involves numbers other than one; for example, when counting money, counting out change, "counting by twos" (2, 4, 6, 8, 10, 12, ...), or "counting by fives" (5, 10, 15, 20, 25, ...).