Texas Math Models

Try “number line” or “4.5D”

Two of each

12 + 7 + 12 + 7 = 38 units G3–4

two lengths and two widths, every rectangle67127(2 × 6) + (2 × 7)12 + 14 = 26(2 × 12) + (2 × 7)24 + 14 = 38green sides are the lengths, amber sides the widths

How this one works

How

two long sides and two short ones. Double each, then add.

Best when

you’d rather multiply than add four numbers.

seen one of these on a test? See it on a real question: TEKS 3.7B, perimeter, and a missing side, or TEKS 4.5D, perimeter and area of rectangles.

The same problem, other ways