Primary students (K-2): counting, patterns, even/odd numbers
Intermediate students (3-5): even/odd numbers, fractions
Quite simply, this is a number line divided into fourths. I color-coordinated the tick marks so that even whole numbers were light blue, odd whole numbers were red, fourths were green, halves were yellow, three-fourths were purple. Then I put a pink dot right at the half-way mark.
For upper elementary students, the number line also shows equivalent fractions. For example, 1/2 is also equal to 2/4.
"The dot is at 2 2/4 or 2 1/2."
"There is a color pattern. And there is a dot in the middle."
"It's a number line."
"There are 20/4 in all on the graph."