Suppose 255,113 people live in a city is it reasonable to say that about 300,00 live in the city? use the number line to you solve the problem .

This is no a reasonable statement. While 255,113 is rounded to the nearest 100,000 (300,000), this does not really provide an accurate estimate because the value is 55,000 off. A more reasonable estimate would be 250,000 or 260,000 people living in the city.