Are you trying to do a search or perform a calculation? All other things being equal, Google search interprets the $
as the symbol for a US Dollar. The other 24 dollar currencies can't be specified using just the $ symbol.
- You specified an input currency (dollars $)
- USD is the primary $ currency and the default when referring to dollars without additional context
- Google Search is incorporating the currency you specified in the search
- Your search terms are triggering the conversion
- If it were a straight mathematical calculation
(10/1)*(12*1)
or ($10/1)*(12*1)
or 10*12
or $10*12
it would not be triggering the conversion.
- You are not specifying an output currency
- When Google Search interpreted your question as a conversion without an output currency, it defaulted to what it believes your local currency to be.
- You can also specify an output currency:
eg. $10/month*12 months=$
or $10/month*12 months=AU$
Takeaways
- If you are using Google Search as a calculator, and the currency is not relevant, it shouldn't be included.
- If a currency (input or output) is specified, do so unambiguously.
- If you build your calculations using numbers and standard mathematical operators, there is less likely to be any misinterpretation by Google Search of what you expect it to return.
Google Search is predicated on making untold assumptions on users' behalf. It doesn't know in advance what will be entered, nor the role it is expected to fill. Calculator? Map? Research assistant? Personal shopper? News aggregator?
While it will try to guess what results are preferred based on the query, it also allows users to narrow the scope, for example, by switching to calculation mode, or searching only in Maps, etc.
This is extra work for a user that can be avoided if search queries are already structured to return what they prefer.
Currency aside, correctly identifying your search query as a calculation/conversion question, and returning the correct result in the top spot is impressive to me.