Why the result does change when ı add other rows in Matrix?

I am trying basic multiplication on Matlab. For the first row, it calculates in true way. But when ı add other rows, it calculates first row wrong.

l_1=600  
A= 48.6
K =  [12, 6*(l_1), -12 ,  6*(l_1) ;
     6*(l_1),  4*(l_1)^2 , -6*(l_1),  2*(l_1)^2 ;
     -12,  -6*(l_1), (12),  -6*(l_1)  ; 
     6*(l_1),  2*(l_1)^2,  -6*(l_1), 4*(l_1)^2 ]
K_result=K.*A

and the result is 

K_result =

   1.0e+07 *

    0.0001    0.0175   -0.0001    0.0175
    0.0175    7.0000   -0.0175    3.5000
   -0.0001   -0.0175    0.0001   -0.0175
    0.0175    3.5000   -0.0175    7.0000
    
    it doesnt calculate A*12 the result must be 583.3 but it shows 0.0001. When i just calculate first row it calculates in true. 
    K =  [12, 6*(l_1), -(12),  6*(l_1)]
    K_result=K.*A
   
    K_result =

   1.0e+05 *

    0.0058    1.7500   -0.0058    1.7500

Answer 1

[Kevin Holly]

It is giving the correct result. It is just rounded. I changed format to long below.

l_1=600; 
A= 48.6;
K =  [12, 6*(l_1), -12 ,  6*(l_1) ;
     6*(l_1),  4*(l_1)^2 , -6*(l_1),  2*(l_1)^2 ;
     -12,  -6*(l_1), (12),  -6*(l_1)  ; 
     6*(l_1),  2*(l_1)^2,  -6*(l_1), 4*(l_1)^2 ];
K_result=K.*A

K_result = 4×4

1.0e+07 * 0.0001 0.0175 -0.0001 0.0175 0.0175 6.9984 -0.0175 3.4992 -0.0001 -0.0175 0.0001 -0.0175 0.0175 3.4992 -0.0175 6.9984

format long
K_result=K.*A

K_result = 4×4

1.0e+07 * 0.000058320000000 0.017496000000000 -0.000058320000000 0.017496000000000 0.017496000000000 6.998400000000000 -0.017496000000000 3.499200000000000 -0.000058320000000 -0.017496000000000 0.000058320000000 -0.017496000000000 0.017496000000000 3.499200000000000 -0.017496000000000 6.998400000000000

[Merve Ala]

Oh thank you so much

[Steven Lord]

In this case IMO format longg is even better.

l_1=600; 
A= 48.6;
K =  [12, 6*(l_1), -12 ,  6*(l_1) ;
     6*(l_1),  4*(l_1)^2 , -6*(l_1),  2*(l_1)^2 ;
     -12,  -6*(l_1), (12),  -6*(l_1)  ; 
     6*(l_1),  2*(l_1)^2,  -6*(l_1), 4*(l_1)^2 ];
format longg
K_result=K.*A

K_result = 4×4

1.0e+00 * 583.2 174960 -583.2 174960 174960 69984000 -174960 34992000 -583.2 -174960 583.2 -174960 174960 34992000 -174960 69984000