These are the basic single digit Subtraction facts 1s through 9s. Each of the 26 levels, A through Z, introduces two facts and their reverses. You can see in the picture above of Set C, I have outlined the new facts in red.
Students practice orally with a partner, reading and answering the facts going around the outside of the sheet. The partner has the answer key. Then the two students switch roles. After practice everyone takes a one minute test on the facts in the box–which are only the facts learned up to this level. Each student has individual goals based on writing speed, but no one can pass a level if there are any errors. You must give the special Writing Speed Test to set individual goals for your students.
Students should be able to pass a level in a week, if they practice the right way. To the right you can see the sequence of facts that will be learned in the Subtraction 1s-9s program. The program uses the four forms–that can be found in the forms and information drawer.
The most succinct way to be introduced to this program is this 8 minute video.