bc: get the sum of a list of num

You can use grep + paste + bc

$ grep -oE '[0-9]+' file
10
10
20
20
20

$ grep -oE '[0-9]+' file | paste -s -d + - 
10+10+20+20+20

$ grep -oE '[0-9]+' file | paste -s -d + - | bc
80

instead grep, you can use cut

$ cut -c 8- file

or just awk

$ awk '{print $NF}' file

BUT if you can use awk, you can sum using awk

$ awk '{total += $NF} END { print total }' file