How to sum these variables into one variable?

So I stored object property values inside these variables, and i want to sum them.
How to do that, and what would be a better way without making variable for each property?

console.log(frequencyCounter1);//{a: 5, b: 2, r: 2, c: 1, d: 1}
        let A = frequencyCounter1.a;
        let E = frequencyCounter1.e;
        let I = frequencyCounter1.i;
        let O = frequencyCounter1.o;
        let U = frequencyCounter1.u;
        console.log(A); //returns 5

you cant sum variables its NaN

Don’t your variables contain numbers?

they do, but try to sum them and see the output

I don’t know what you mean.