Number format in formula with text

How do I get the latter sum of this formula to return the value in percentage, not as a decimal number:

="No of girls: "&(SUM(AT2:AT260))&" / % girls:"&((SUM(AT2:AT260)/(SUM(AS2:AS260))))

I.e. as result I would want:
No of girls: 3 / % girls: 43 %

NOT
No of girls: 3 / % girls:0.428571428571429

Is it even possible?

Thanks folks!

Try:

="No of girls: "&(SUM(AT2:AT260))&" / % girls:"&TEXT((SUM(AT2:AT260)/(SUM(AS2:AS260))),"0.###%")

Works. Brilliant, thank you!

You're welcome