Very basic question... selecting multiple images in Elements for time lapse

I'm beating my head off the wall...

I'm playing with time lapse in Elements 14.  I've loaded 10 images to play with time stretch.  I should be able to select the first image in the 10 image series in the video time frame, hold down Shift, then select the last image in the 10 image series and have the entire 10 images showing as selected.  Sure, I can hold down Shift and select each and every image I want in the series.  This is easy enough with 10 images, but will be a colossal waste of time with 400 images in the eventual time lapse.  I'm know I'm being boneheaded and just missing something... but how to you easily select multiple images in a time frame series in Elements 14????  Thanks for your help!