5G–2: Compare areas and calculate the area of rectangles (including squares) using standard units. Applies arithmetic to geometry, essential for understanding properties of shapes and for real-life problem solving.
Going through all 6 lessons of this unit (unit 10) is really worthwhile, as it will give a full intuition about area, from the very beginning of counting squares, to the end of using the area formula and even filling in missing gaps for given areas of rectangles.