Giải bài 3 trang 154 - SGK Toán lớp 5

Hướng dẫn:

$1ha = 1hm^2 \\ 1ha = 10 \, 000m^2$

Bài giải:

$a) \\ 65 \,000\text{m}^2 = \dfrac{65 \, 000}{10 \, 000} \text{ha} = 6,5 \text{ha}\\ 846\, 000\text{m}^2 = \dfrac{846\,000}{10 \, 000}ha = 84,6 \text{ha} \\ 5\,000\text{m}^2 = \dfrac{5000}{10 \, 000}\text{ha} = 0,5 \text{ha} \\ $

$b)\\ 6\text{km}^2 = 600 \text{ha} \\ 9,2\text{km}^2 = 920\text{ha} \\ 0,3\text{km}^2 = 30\text{ha}$