3 Don’ts in teaching word problem solving with bar models

If your child is using Singapore Math in their school, chances are you are familiar with bar models. Bar-modeling is a tool to help students visualize the problem and then write the corresponding equation to solve the problem. When learned properly, it is a very useful tool which enables students as early as the 5th grade to solve word problems typically given in High school and College Entrance Tests. For example:

The ratio of the price of a bag to the price of a book was 9:4. During a sale, the prices of the bag and book were reduced by $7 and $2 respectively. The ratio of the price of the bag to the price of the book became 2:1. How much was the price of the bag at first?

Here are some tips on how NOT to teach the bar models:

  1.  Do not make your kids memorize certain keywords and associate them with specific operations. Ex.  “If you see the word altogether, then you have to add” or “How many are left” is subtraction.  Relying on keywords might work for simple 1 step word problems but not with more complex, multi-step word problems such as the above.
  2. Do not make your kids write the equations before drawing the bar model. Some parents think of the answer or operation, and then draw a model based on the answer.  When bar models are drawn prior to the equations, it helps the student break down and visualize the problem.
  3. Do not use algebra.  Mathematically inclined and well-meaning parents will be able to solve 4th to 6th grade word problems using algebra but they will have a hard time explaining the approach to their kids. Extensive practice with the bar-model approach is the fastest way for your kids to solve those kinds of word problems.

To effectively learn how to use bar-models, students should be exposed to a variety of models starting from the simple (part-whole, comparison) to the more complex (repeated identity & unitary approach) in a systematic program with appropriate supporting materials and a properly designed progression.