You may go the super easy way and choose 1 as the whole number and 0.28 as the decimal number. Then you'd obviously have [tex] 1\cdot 0.28=0.28 [/tex]
Otherwise, to be a bit more creative, you can observe that
[tex] 0.28=\dfrac{28}{100} = \dfrac{14}{50} = \dfrac{7}{25} = 7\cdot \dfrac{1}{25} [/tex]
And since 1/25=0.04, you can also choose 7 as the integer, and 0.04 as the decimal to get
[tex] 7\cdot 0.04=0.28 [/tex]
