Since the uploading of the packet tracer video CISCO HAS CHANGED IT. No worries you will just need to add the command on R1:
int s0/0/0
ip summary-address eigrp 1 172.31.0.0 255.255.254.0 5
and on R2:
int s0/0/1
ip summary-address eigrp 1 10.10.0.0 255.255.248.0 5
This is just another way to create summary addresses. The 5 on the end is of course the administrative distance.
If you have any questions please comment below.
Peace,
Whaleh8er