Vì 1m2 = 100 dm2 = 10000 cm2 .
25 dm2 \(=\dfrac{25}{100}\)\(=\dfrac{25}{4.25}\) \(=\dfrac{1}{4}\) m2 ;
36 dm2 \(=\dfrac{36}{100}\) \(=\dfrac{9.4}{25.4}\)\(=\dfrac{9}{25}\) m2 ;
450 cm2 \(=\dfrac{450}{10000}\) \(=\dfrac{9.50}{200.50}\)\(=\dfrac{9}{200}\) m2;
575 cm2 \(=\dfrac{575}{10000}\)\(=\dfrac{23.25}{400.25}\)\(=\dfrac{23}{400}\) m2 .