600. You stack the problem and then multiply the 0s by the 2, so you have 00 under the problem. Then, you do 2x3, which gives you 6, which goes before the zeroes. Or, you can just do it like 300x2, cross out any zeroes, do the problem without any zeroes (in our case 600), and then add the zeroes you crossed out at the end of your product (600). (this is a trick my teacher taught me for numbers that end in zero getting multiplied, but when you use it to divide you don't put the zeroes you crossed out from before onto the product).