How can I add a character into a specified positio

Question

I have a varchar field like:

195500
122222200

I need to change these values to:

1955.00
1222222.00

Answer 1

declare @a varchar(10) = 'aaa' select concat(@a,'.00')

Answer 2

try this

Declare @s varchar(50) = '1234567812333445'
Select Stuff(@s, Len(@s)-1, 0, '.')
--> 12345678123334.45

fiddle demo

Answer 3

CREATE TABLE #T ( Value VARCHAR(20) )
INSERT INTO #T ( Value ) VALUES ( 195500 ), ( 122222200)

SELECT 
    Value
,   NewValue = CONVERT(DECIMAL(17,2),CONVERT(DECIMAL,Value) / 100)
FROM #T

|     Value |   NewValue |
|-----------|------------|
|    195500 |    1955.00 |
| 122222200 | 1222222.00 |