More on Using Models: Multiplication & Division

To ensure that the children understand the different variables in a word problem, a checklist can be done as shown in this child's work. I used these 3 examples on page 53 of the workbook to explain to the children.

Using the above checklist, the children can identify 2 out of the 3 variables. There will definitely be one unknown (box not checked). As stated in this post, the children have to know the following- using question (b) as an example:

• number of groups (4 plates)
• things (20 chicken wings)
• number of things in each group (unknown)

When the children translate these information into the bar models, they need to know that the number of groups mean the number of bars they need to draw. That is 4 bars in this example. Next, they need to state another information given- 20. They will draw the braces { } and write '20' under the whole bar model. Finally, the unknown is represented by a question mark (?).
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Math textbook page 136

We will replace bar models with dotted lines when:

1. the number of groups is not given (if that is what we need to find)
2. there are too many groups to be represented (e.g. 45 groups) 

Hope this helps!