Its not necessary u must finish all of it once u open it. Take the amount u need and tie it with rubberband so that air cant go in. Unless ure super duper fat then u can finish one packet straight.

Haiya amoi, just take as per your serving lah, see how much u can eat, that much u take lah. Take as per your stomachs need. How much u can eat, that much u put loh. Simple maaa. This wan also need Einstein meh?

I think for your body, 10 to 15 sticks enuff loh. That thing looks small dry, when u cook it, it will become double the size. So 10 to 15 sticks should be fine.