What is the greatest three-digit multiple of 19?
I want to find the largest possible value of n such that 19n is a three-digit number. That means 19n has to be less than 1000, or n has to be less than 1000/19. I can use a calculator to find that 1000/19 is about 52.63158. That means n has to be an integer less than or equal to 52. The largest such integer is 52, so the greatest three-digit multiple of 19 is 19 times 52. I can use a calculator or mental math to find that 19 times 52 is 988. 