Best way to tone my tum tum?!?

I want to tone my tummy. I'm 5'1 and weigh 116. Im not fat but im flabby and need to tone my tummy. I've tried sit ups i do 120 of them every other day. Ive been doing this for a while (5 months) and still nothing. I already eat right I don't eat much i cant eat much. I eat about 1,300 calories each day. SO yea. I don't have money to buy exercise machines and i rather not ask to buy anything to help. I do have dum bells and a hola hoop though? Any thing that's easy to do?!