Join Result Unknown (JRU) problems can be solved by direct modeling using the Join All direct modeling strategy. The Join all strategy looks like this:
Problem: Mary had 4 pencils. Her teacher gave her 2 more pencils. How many pencils does Mary have now?
Joining all strategy:
Separate Result Unknown (SRU) problems can be solved by the Separate from strategy,
Problem: Kyle had 6 pencils. He gave 2 of his pencils to Mike. How many pencils does Kyle have now?
Separating from strategy:
Join Change Unknown (JCU): problems can be solved by the Join To strategy.
Problem: Ted made 4 paper airplanes in the morning. How many more paper airplanes does he need to make to have 6 paper airplanes?
Join to strategy:
Compare, difference unknown (CDU) problems can be direct modeled using a matching or compare strategy.
Problem: Kelly has 9 pencils. John has 6 pencils. How many more pencils does Kelly have than John?
Matching/comparing strategy: