With this spreadsheet you can create worksheets with 100 problems. You simply put the range of top addends from 1 - 10 and the range of bottom addends 1 - 10. If you select 7 to 7 on the top and 1 to 10 on the bottom or vice versa, you will get 100 problems to practice the 7s. You can select F9 to recalculate the sheet.