Unwanted Exponential output in matlab calculation

Hi All I am solving multiple regression problem using vectors entered at run time. Some of the output variables default to exponential format and inspection with manual cal shows they're wrong. I underestimated it; spent all day yesterday to fix it without success hence I am sharing it. I've commented on the wrong outputs below. Thanks, in advance.

x1 = input('Enter x1 data:');
x2 = input('Enter x2 data:');
y = input('Enter y data:');
a = mean(x1);b= mean(x2);c = mean(y);
mean_of_x1 = a
mean_of_x2 = b
mean_of_y = c

 table =[y; x1; x2; y-c; (y-c).^2; x1-a; x2-b;(x1-a).*(x2-b);(x1-a).^2;(x2-b).^2; (x1-a).*(y-c);(x2-b).*(y-c)];

fprintf('y, x1, x2, y-c, (y-c).^2, x1-a, x2-b, (x1-a).*(x2-b), (x1-a).^2, (x2-b).^2, (x1-a).*(y-c),(x1-a).*(y-c);(x2-b).*(y-c)\n ')

fprintf('%4.2f %8.2f %10.2f %12.2f %14.2f %16.2f %18.2f %20.2f %22.2f %24.2f %26.2f %28.2f\n', table)

 summation_of_x1 = sum(x1)
summation_of_x2= sum(x2)
summation_of_y = sum(y)
d = y-c;
summation_of_y_minus_C = sum(d)% THIS DEFAULTS TO EXPONENTIAL EVEN WITH 'SMALL DATA'

summaion_of_y_minus_c_square=sum((y-c).^2)

e = x1-a;

 summation_of_x1_minus_A=sum(e)
 f = x2-b ;

 summation_of_x2_minus_B = sum(f)% THIS ALSO DEFAULTS TO EXPO
 sumation_of_product_x1_minus_A_and_x2_minus_B = sum((x1-a).*(x2-b))
Summation_x1_minus_A_square= sum((x1-a).^2)
  Summation_x2_minus_B_Square= sum((x2-b).^2)
  summation_product_x1_minus_A_and_y_mnius_c = sum((x1-a).*(y-c))
  sumation_product_x2_minus_B_and_y_minus_c = sum((x2-b).*(y-c))
x1=[3, 1, 9, 5, 2]; x2=[12, 5, 11, 22, 3]; y=[28,9, 5, 7, 32]% My test data I've used many times without success