Final answer:
In a given list of numbers, the number that comes first when arranged from least to greatest is 3. This is deduced applying the standard counting system and the concept of order of magnitude.
Step-by-step explanation:
The question asks for which number would come first when the list of numbers provided are arranged from least to greatest. Looking at the options given, we have one definitive number mentioned, which is 4.5 and 3. But for all numbers in a standard decimal system, the smallest number will always be the one that has the lowest value itself. Hence in this scenario, the number/s that come/s first when the numbers are listed from least to greatest is 3. The idea of counting system and order of magnitude is essential to know here, which is that each place in our numbering system is ten times greater than the place to its right. This concept helps us in understanding and comparing numbers swiftly.
Learn more about Ordering numbers