To convert kilos to grams multiply by 1000. I've generated some hopefully helpful examples randomly below, as with most random sentences please excuse the repetitive and occasionally comic outcomes.
You have 330 kilos of potatoes but you need to know how many grams that is. To get the answer multiply by 1000 which gives you 330000 grams.
You've got 310 kilos of barley but someone only wants to buy that in units of grams, to change the units multiply by 1000. Now you have 310000 grams.
To convert 760 kilos into grams multiply by 1000 giving 760000 grams.
How many grams of beetroot are there in 200 kilos? Just multiply by 1000 to get the answer of 200000 grams.