Within the map, zoom in close enough to see ZCTAs. If you want to see the total population for a particular ZCTA, simply put your mouse pointer over that ZCTA - population will be the top number in the lower left Tool Kit display as long as the Information Card is enabled (if it is not, simply click the “i” icon). If you need total population for a group of ZCTAs, select them from the map and click the Data Table icon (looks like four squares together) in the lower left Tool Kit. The top row in the Data Table will summarize all selected ZCTAs.