Put in turbo mode(shift+green flag), click the green flag, say how many primes you want(2+), then wait. 'checkingnumber' is the number it's currently checking. 2.0-release 2.1-supposedly made doubly fast 2.2-made incredibly slightly faster
Added more cloud stuff at cirecire's request: Now when you generate primes they are added to the cloud and loaded in when you start the project Taken from my prime number generator https://scratch.mit.edu/projects/17986300/