Budući da je $1\text{ m} = 10\text{ dm}$$1\text{ m} = 10\text{ dm}$, za kvadratne jedinice vrijedi:
$$1\text{ m}^2 = (10\text{ dm})^2 = 100\text{ dm}^2$$$1\text{ m}^2 = (10\text{ dm})^2 = 100\text{ dm}^2$

Stoga je:
$$3.5\text{ m}^2 = 3.5 \cdot 100 = 350\text{ dm}^2$$$3.5\text{ m}^2 = 3.5 \cdot 100 = 350\text{ dm}^2$

Točan odgovor: C) $350\text{ dm}^2$$350\text{ dm}^2$