Can someone please explain this? In units

Date purch sold bal
4/1 600-6.00 600
4/3 500-10.00 100
4/4 1500-6.08 1600
4/8 800-6.40 2400
4/9 1400-10.00 1000
4/11 600-11.00 400

How do you start lifo and fifo? I don't think I am doing it correctly. I kept beg. Bal at 600 sold 500-10.00 which left 100, then??

Not very clear about the problem except date. For 4/1, what's the 600 on the right? Is it balance of the date or the sold unit of the date? I guess sold unit will be more likely.