Estimate lengths involving inches, feet, centimeters, and meters. Useful skill for looking at maps and estimating distance. Also useful for selecting an appropriate tool. For example, if something is long, I will use a tape measure. If it’s short I’ll use a ruler, simply because a ruler is easier to wield.

Do these Khan Academy exercises:

Conclude by leading this investigation:

Celtic Counting (counting, proof)

by MathPickle

2.MD.A.3: Estimate lengths using units of inches, feet, centimeters, and meters.