i think it might be easier to understand if i change decimals to fractions, so lets start ;)
[tex]15.249=15\frac{249}{1000} [/tex]
[tex]15.3=15.300=15\frac{300}{1000} [/tex]
[tex]15.05=15.050=15\frac{50}{1000} [/tex]
[tex]15.009=15\frac{9}{1000} [/tex]
[tex]15.25=15.250=15\frac{250}{1000} [/tex]
denominators are the same so now you only have to compare numerators (biger numerator = greater fraction)
so:
[tex]15\frac{9}{1000}<15\frac{50}{1000}<15\frac{249}{1000}<15\frac{250}{1000}<15\frac{300}{1000}[/tex]
it means that:
[tex]15.009<15.05<15.249<15.25<5.3[/tex]
