Registan,
how about 4100?
There are 4x1000 and 30+40+20+10=100 ----- 4000+100=4100
Or
1000+30=1030,
1030+1000=2030,
2030+40=2070,
2070+1000=3070,
3070+20=3090,
3090+1000=4090,
4090+10=4100
So total is 4100, isn't it?
i tried, i wasn't that good at mathematics so if I'm wrong sorry....
The Alchemist