add a part in a cell

[KATSALAS]

how to add in a cell that the content has a number at the end...
example:

a1
a2
a3
......
a1000

to

a1.pdf
a2.pdf
a3.pdf
.........
a1000.pdf

 

[Oaktree]

One way is B1=A1&".pdf" then copy B1 down through B1000

 

[babycody]

Is this what you are looking for?

Book2
	A	B	C	D
1	a1	a1.pdf
2	a2	a2.pdf
3	a3	a3.pdf
4	a4	a4.pdf
5	a5	a5.pdf
6	a6	a6.pdf
7	a7	a7.pdf
8	a8	a8.pdf
9	a9	a9.pdf
10	a10	a10.pdf
11	a11	a11.pdf
12	a12	a12.pdf
13	a13	a13.pdf
14	a14	a14.pdf
15	a15	a15.pdf
Sheet1

Another option :

\a#."pdf" could be used, if you are entering the number only into the cells, by going to format>cells>number tab>custom and pasting this custom format into the Type: box. If it already has an "a" before the numbers then someone who is better than me at custom formats could probably help you with that.