Calculating decimal places in a non decimal format (ie sixes not tens)

Hello all,
I am trying to add numbers where the decimal places equal a whole number when they reach 6.
For example:
Where 1.3 + 1.3 = 3
Or 1.3 + 2 = 3.3
Or 2 + 0.2 = 2.2
Or 21.5 + 4.2 = 26.1

Is there a way to make this work in excel. Any help greatly appreciated. Thanks.

With your numbers in A1 and B1, put this formula in C1:

=INT(A1)+INT(B1)+INT((MOD(A1,1)*10+MOD(B1,1)*10)/6)+MOD((MOD(A1,1)*10+MOD(B1,1)*10),6)/10

then copy down as required.

Hope this helps.

Pete

Thank you to both and each solution works, if however I wanted to add numbers over a range of cells, say A1:A7 how would I express it to get the result? Thank you

Thank you very much for your assistance