Think about concepts you might want to combine with your topic. You can add with AND to make the search narrower. Remove concepts to broaden the search if you get very few or no results.
|Toys||Young children||Mathematics education|
|FINGER calculation||Middle school students||Mathematics--Study & teaching|
|Teaching aids and devices||MATHEMATICAL ability in children||Elementary school mathematics|
The success of your search may depend upon the terminology or search terms you select.
Be flexible. Be willing to try synonyms, to try more specific or broader terms.
Check the terms used in records you retrieve. Reuse words that match your topic. This is called "using language in context."
Even though the record below describes an article that may not be considered a "professional journal," the terms used in it are worth trying.