Question

What is an expression so that the product of a whole number and a decimal is 0.28

Answer 1

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 $1\cdot 0.28=0.28$

Otherwise, to be a bit more creative, you can observe that

$0.28=\dfrac{28}{100} = \dfrac{14}{50} = \dfrac{7}{25} = 7\cdot \dfrac{1}{25}$

And since 1/25=0.04, you can also choose 7 as the integer, and 0.04 as the decimal to get

$7\cdot 0.04=0.28$