answersLogoWhite

0


Best Answer

The average of two numbers is the number directly between the two. For example, the average of 85 and 89 is 87, because 87 is directly between 85 and 89.

The number directly between two numbers is half of the count from one number to the other, added to the lesser number. Starting from 85 and going to 89, you count four numbers (86, 87, 88, 89). Half of four is two, and two added to 85 is 87.

To find the average of more than two numbers, I often subtract a certain amount from a greater number and add the same amount to a lesser number until I can see the average. For example, to find the average of 100, 90, 85 and 89, I would start by changing the 100 to 95 and the 85 to 90. So then we have 95, 90, 90 and 89. Since there's a difference of six from 89 to 95, I would take three from 95 and add it to 89, making 92, 92, 90 and 90. Now I see that each pair of 92 and 90 could be changed to a pair of 91's. Since the average of 91, 91, 91 and 91 is 91, the average of 100, 90, 85 and 89 is 91. No calculator needed.

User Avatar

Wiki User

11y ago
This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: How do you calculate an average of a set of numbers by only counting?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Related questions

What can only have value by counting numbers?

Data


Is negative four a counting number?

No, only positive integers are considered counting numbers.


What are the whole numbers that are not counting numbers?

'0' is the only whole number that is not a counting number. Negative integers do not belong to whole numbers.


Why aren't fractions counting numbers?

This is a bit arbitrary. Mathematicians and educators have agreed that counting numbers are to be whole numbers only. There has to be some consistent use for phrases like "counting number", or we would have complete confusion.


What can only have value that are counting numbers?

Positive integer solutions.


How many numbers will divide into 10?

Amongst counting numbers (positive integers) only 4.


What is the arithmetic mean of a data set is the measure of center?

It is one measure - not the only one - of a "central tendency". It is the same as the "average". To calculate the average, just add all the numbers, and divide the result by the amount of numbers.


Is the fraction 6 over 7 a natural number?

No natural numbers are the counting numbers only 1,2,3,4,5...


Does the number 18 have 6 factors?

Yes, if you are counting positive numbers only.


Do all square roots of perfect squares are rational numbers?

Yes. Not only that, they are counting numbers.


What do numbers 4 5 and 9 have in common?

They are the only numbers that have 4 letters, not counting zero: Four Five Nine.


Which prime numbers are also consecutive numbers?

The only numbers that are consecutive and prime (ie. they are counting numbers greater than 1 that follow each other and can only be divided by themselves and 1) are;23