ROUND(number, digits) rounds to that many decimal places: =ROUND(2.678,2) is 2.68. ROUNDUP and ROUNDDOWN always go one way, which is what you need for things like boxes or seats. A digits value of 0 gives a whole number.
Rounding isn't the same as formatting. The decimal buttons only change what the cell shows; the full number is still used in other formulas. ROUND changes the number itself.
Errors tell you what went wrong: #DIV/0! divides by zero or an empty cell, #N/A is a lookup that found nothing, #NAME? is a misspelt function or text without quotes, #VALUE! is maths on text, and #REF! points at a cell that no longer exists.
IFERROR(formula, fallback) shows the fallback instead of any error. Use it where an error is expected (a new shop with no sales last year), not to hide mistakes you haven't looked at.
Practice
What does one item cost? Divide and round to two decimals in D2 (copied to D4).
A
B
C
D
1
Pack
Price
Items
Each
2
Eggs
3.49
12
3
Socks
9.99
7
4
Pens
4
3
D2
More info
Quick reference
ROUND(number, digits)
Rounds to the nearest.
ROUNDUP / ROUNDDOWN
Always up / always down.
IFERROR(formula, fallback)
The fallback instead of an error.
#DIV/0! #N/A #NAME? #VALUE! #REF!
Divided by zero; not found; unknown name; maths on text; missing cell.
The practice answers
Other formulas that give the same results count too.
What does one item cost? Divide and round to two decimals in D2 (copied to D4). =ROUND(B2/C2,2)
130 cups, 24 to a box. How many boxes do you need? Whole boxes only, in B3. =ROUNDUP(B1/B2,0)
Growth is this year divided by last year, minus 1. Shop B is new, so show "New" instead of an error, in D2 (copied to D4). =IFERROR(C2/B2-1,"New")
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