There are currently six investigations: one based on positive & negative numbers; one on sequences; one on area/perimeter; one on polyominoes; one on handling data; and the sixth on probability.
I cannot see the video.
Hello - I am the original creator of this resource and originally uploaded it to TES in the United Kingdom. The level ladders on the assessment pages link to the levels of the UK National Curriculum, but hopefully they will be useful to US teachers attempting to assess progress against various strands. I hope you find the resource useful!