Rhubarb Crumble

3 cups diced rhubarb
1 cup granulated sugar
1/2 teaspoon salt
1 tablespoon instant tapioca
1/2 teaspoon cinnamon
1 cup oatmeal
1/4 cup flour
1/3 cup brown sugar
1/4 cup butter

Combine rhubarb, sugar, salt, tapioca and cinnamon. Place in a square baking pan. Combine oatmeal, flour and brown sugar. Cut butter in until crumbly. Spread over rhubarb mixture. Bake at 350 degrees F for 30 minutes.