What is the least number that rounds to 80 when rounded to nearest 10?

To find the least number that rounds to 80 when rounded to the nearest 10, we need to consider numbers between 75 and 84. The midpoint between 75 and 84 is 79.5. When rounded to the nearest 10, 79.5 rounds up to 80. Therefore, the least number that rounds to 80 when rounded to the nearest 10 is 79.