Apparently we all come from good stock!
I remember struggling with multiplication, division and fractions...I lost most of my summer after 3rd grade being drilled by my grandmother with math exercises and being tested with flash-cards and spot tests...I wasn't allowed to leave the house until I made satisfactory progress each day. Since she taught all grades in a one-room schoolhouse in SW MN, she knew how to teach!
To this day I do most math in my head and when I need help I rarely bust out the calculator. I do use Excel a lot at work, but volume data-crunching and tabulation hard to avoid for an accountant! But being able to do math in your head does make it easier to catch formula errors!