Ask a question the source can answer
Begin with a place, date and subject: the population recorded in a census, a government projection for a later date, a household survey indicator or registered events. For a simple population lookup, the national and state pages provide a starting point. For a specialised question, use the topic guide to find the appropriate source family.
If two websites give different totals, look for a different year, geographic boundary, revision or type of evidence before deciding that one is wrong.
Read the label beside the number
Check the unit and denominator. People, households, arrivals and administrative identities are different quantities. A percentage may describe an age group, a labour force or sampled households rather than the whole country. A table expressed in thousands retains that precision even when its figures are displayed as people.
For cities, look for municipality or urban agglomeration. For state comparisons, check whether the figures use historical or current boundaries. The familiar place name alone does not settle the geographic question.
Quote the figure with enough context
A useful citation identifies the publisher, measure, reference period and source link. Add the projection vintage, survey status or important coverage restriction where relevant. The page’s review date tells you when the source was checked; it is separate from the date the figure describes.
Use the original linked table to confirm a figure that matters to your work. When the page is a source guide without reproduced values, follow it to the publisher rather than treating the missing number as zero or guessing a current total.