It will usually be simplest to portion out your rice in whole cups. For example, two people sharing a cozy meal may only eat two to three cups of rice, whereas a larger meal may require six to eight. Working with even quantities will make it much easier to figure out exactly how much water you need to produce perfectly cooked rice.   Using a dry measuring cup to scoop your rice will help you avoid any troublesome guesswork. For best results, only prepare as much rice as you plan on eating. Leftover rice doesn’t reheat well. Place the brown rice in a mesh strainer or sieve and run it under the faucet, circling the strainer beneath the stream. This will rinse away most of the starch, which will prevent the grains from becoming sticky when cooked. Continue washing the rice until the water runs clear.  You may notice that the water draining out of the rice has a slightly milky appearance. This is normal. Shake out as much excess water as you can before cooking the rice. Place the newly washed rice in the bottom of the cooker and spread it out. When preparing a lot of rice at once, make sure it’s properly distributed so that it will cook evenly. Don’t add more rice to the rice cooker than it can hold at one time. If you need to prepare an especially large amount, do it in batches.

TL;DR in Vietnamese:
Đong lượng gạo mà bạn muốn nấu. Làm sạch gạo bằng nước lạnh. Cho gạo vào nồi cơm điện.