2200
70 and 30
-85
-52
-154
Multiply 2100 by 0.3 You can also do it this was- 30% is 30 for each 100- and you have 21 100's. 30 X 21. Or 3X 21 (63) and add a zero.
200
105
Instead of adding each digit in turn, acknowledge that there are 100 numbers to add, and then multiply that by the average of 1 and 100.Ie. 100×(1+100)÷2=100×101;÷2100×101;÷2=50×101=5050So, in short, the answer is: 5050
114
27
it's 100...
26
41