Different Ways to Teach Subtraction

There are many methods for teaching the essential skill of subtraction.

Teaching subtraction is an essential part of elementary math class. Because of the age of students in low-level math courses, teachers may prefer to avoid using the standard textbook approach to teaching subtraction. There are a variety of different ways you may successfully teach students how to subtract.

Word Problems

Making subtraction appear to be a practical method of solving problems can allow students to integrate the method of subtraction into a skill set of problem-solving. Subtraction word problems basically introduce a scenario in which some of a set of things go missing. For example, "I had 3 apples and ate 2 of them. How many are left?" is a basic subtraction word problem. Students can see the practicality of this type of word problem and it can prepare them for more rigorous lessons in subtraction.

Finding Dates

This method of teaching subtraction allows students to essentially learn subtraction on their own. For this method, you can use any materials with dates on them, such as books with copyright dates or canned foods with expiration dates. Give students these objects and ask them to find the age of the object. Students will quickly learn that subtraction is addition in reverse by practice by counting from the date on the object to the current date. You can warm up students to this activity by writing the date you were born on the board and asking students to tell you your age -- if you dare.

Separate Problems

You can introduce students to subtraction by disguising subtraction problems as addition problems. Essentially, design addition problems with given answers but missing parts. For example, "4 + ? = 6" is a basic, separate problem. Through such a lesson, students will be well-prepared to learn how to rearrange such problems using the subtraction symbol (i.e., 6 - 4 = ?).

Compare Problems

Compare problems are subtraction problems in disguise. In a sense, compare problems are the combination of word problems and separate problems. An example of a compare problem is "Bob has 3 brothers. Steve has 2 brothers. How many more brothers does Bob have?" It has been shown that compare problems are enormously effective in helping students improve their subtraction skills to the point of gaining the ability to subtract large quantities.

References

• Chapin, Suzanne H; Math Matters: Understanding the Math you Teach, Grades K-8; 2006