In a town, there are four primary schools. Two of them can teach 400 students at a time, and the other two 340 students at a time. How many students at a time in total, can these four primary schools teach? Think carefully first, then make a decision:
Two schools can teach 400 students, so in total, they can teach 2 * 400 = 800 students. The other two schools can teach 340 students, which gives 2 * 340 = 680 students in total. So all four schools can teach 800 + 680 = 1480 students at a time. So, the answer is 1480.