Grandma's Snickerdoodles

1 C. butter, softened
1 1/2 C. sugar
2 eggs
2 3/4 C. flour
2 tsp. cream of tartar
1 tsp. baking soda
2 T. sugar
2 tsp. cinnamon

Combine first three ingredients. Blend flour, cream of tartar, soda, and salt. Shape into balls. Roll in sugar/cinnamon mix. Place on ungreased cookie sheet. Bake at 400 for 8 to 10 minutes.