Mean - is the average of something. You basically find the sum of all the numbers then divide the sum by how many numbers you added so for example I have 1,3,4and 2 To find the average you add them first to get 10 then you divide this by 4 since I added 4 numbers.
Median - is the number that falls in the middle. First you gotta sort the numbers from smallest to biggest then pick the one in the middle for example is I have 7,5,9,2and 1. I gotta sort it —-> 1,2,5,7,9 then I pick the number in the middle which is 5. So 5 is the median
Mode- is the number that appears the most times. So if I have the set 3,7,5,3,9,4,1,3 the mode would be 3 because it appears the most times