Converting Compound Units

This unit moves back and forth between writing a quantity as a large unit paired with a small one, as in 1 km 2300 m, and writing it in a single unit. Length conversions from km to km and m and from m to m and cm, and capacity conversions from L to L and mL, are practiced in both directions again and again.

Reading the first decimal place straight off as meters, turning 2.3 km into 2 km 3 m, is the standard error. Any answer where a zero was never filled in should be suspected of it. The reverse direction shifts the places for the same reason, as when 1 L 60 mL is written 1.6 L.

Rewriting a quantity in a small unit paired with a large one, and back again, is practiced here on a new subject, capacity, beyond the length it started with. The conversion between km and m fixed in Length (km and Tape Measure) in grade 3 is the base this rests on. The same skill is needed again before the grade is over, when Speed converts between distance covered per hour and per minute.