A function is a ready-made formula with a name. You write the name, then its inputs in brackets: =SUM(B2:B8) adds up every cell from B2 to B8. B2:B8 is a range: the first cell, a colon, the last cell. A range can be a block too, like A1:C4.
AVERAGE gives the mean, MIN and MAX the smallest and largest, and COUNT how many cells hold numbers. COUNTA counts every cell that isn't empty, words included.
These functions skip text and empty cells in a range, so a heading or a note doesn't break the total. You can also give several inputs separated by commas: =SUM(B2:B4,B9,100).
In some countries, spreadsheets separate inputs with ; instead of ,. The practice grids accept both.
Practice
How many steps this week? Total them in B9.
A
B
1
Day
Steps
2
Mon
6200
3
Tue
8100
4
Wed
5400
5
Thu
9900
6
Fri
7300
7
Sat
12400
8
Sun
4800
9
Total
B9
More info
Quick reference
SUM(range)
Adds the numbers.
AVERAGE(range)
The mean of the numbers.
MIN(range) / MAX(range)
The smallest / largest number.
COUNT(range)
How many cells hold numbers.
COUNTA(range)
How many cells aren't empty.
The practice answers
Other formulas that give the same results count too.
How many steps this week? Total them in B9. =SUM(B2:B8)
What's the average day? Put it in B9. =AVERAGE(B2:B8)
Find the best day in B9 and the worst in B10. Start with the best. =MAX(B2:B8)
One student was away. How many sat the test? Count the scores in B9. =COUNT(B2:B8)
An unofficial course. Not made by or affiliated with Microsoft; Excel is a trademark of Microsoft Corporation.