1000 + 7 = 1007
You could try counting in base 561/3 = 3.825862 (approx).
987/1000
= 7 x 1000 = 7000
Its 500,500. you just work 1000 x 1001 divided by 2
6000.......it's actually 5,100
4100
5370
500,500
1000 + 1000 - 1000 + 1000 = 2000
1000+40=1040 1040+1000=2040 2040+30=2070 2070+1000=3070 3070+20=3090 3090+1000=4000 4000+10=4100
13011
5000 + 8250 + 100 + 1000 + 6500 + 1000 + 6500 + 1500 + 1500 + 10000 + 1000 + 10000 + 100 + 8250 + 5000 + 5000 + 8250 = 78,950