HOW TO SHOW THE 0 AT THE END????

I've got in cell M63 the following formula:
="A5 = € "&O63
And the value that's in cell O63 is 9,10
But it shows only:
A5 = € 9,1
My question is how can I let it show also the 0? So it will show:
A5 = € 9,10
Must I do something with the properties? The 9,10 value is able to change so it can also become 9,15 and then it does show the whole value! How can I let it show the 0 at the end?
Thanks!