How to remove formula in a cell and have only values ??

Hello everyone,

i had prepared profit U& loss a/c, capital a/c and b/s of my client in excel. by mistake i pressed some button that i do not know and due to this wherever i have used formula in there instead of value/amt. formula is appearing.

for. eg.

for example instead of 6 "sum=4+2" is displayed. i want that cell shoudl show only value i.e.6.