You don't use that formula - it doesn't apply at all. Just create a histogram by counting the numbers for each roll
counts = zeros(1,6); % list of how many times each number came up
for r = 1 : numRolls
roll = randi([1 6],1);
counts(roll) = counts(roll)+1;
end
% Now normalize to get fraction of time each number came up.
counts = counts / numRolls; % Multiply by 100 if you want percentage instead of a fraction.
