4.MD.1: Know relative sizes of measurement units within one system of units including km, m, cm; kg, g; lb, oz.; l, ml; hr, min, sec. Within a single system of measurement, express measurements in a larger unit in
terms of a smaller unit. Record measurement equivalents in a twocolumn
table. For example, know that 1 ft is 12 times as long as 1 in.
Express the length of a 4 ft snake as 48 in. Generate a conversion table for
feet and inches listing the number pairs (1, 12), (2, 24), (3, 36), ...
