first of all

I do the homework.

私は宿題をします

I do the math homework.

私は数学の宿題をします

I do the math homework with my younger brother.

私は弟と数学の宿題をします

I do the math homework with my younger brother at home.

私は家で弟と数学の宿題をします

I do the math homework with my younger brother at home today.

私は今日家で弟と数学の宿題をします