It really easy. Just 1x1=1 just add all the zeros. Take the zeros from 10000000000000 and 1000. I got:
1000000000000x1000= 10,000,000,000,000,000
100000 times 10000000000000 is 1,000,000,000,000,000,000
10000000000000
4,970,275,518,360,000,000,000,000
3% of 10000000000000 = 3% * 10000000000000 = 0.03 * 10000000000000 = 300,000,000,000
10000000000000 = 10,000,000,000,000
1000000
10000000000000-3747577 = 9999996252423
10000000000000 = 1013
4-10000000000000 = -9999999999996
100 + 10000000000000 = 10000000000100
213 x 513 = 10000000000000
32732.2719