1. Problem 11: Calculate $$7860 - 2929$$. Step: $$7860 - 2929 = 4931$$. 2. Problem 12: Calculate $$7600 - 3986$$. Step: $$7600 - 3986 = 3614$$. 3. Problem 13: Calculate $$14.95 - 8.24$$. Step: $$14.95 - 8.24 = 6.71$$. 4. Problem 14: Calculate $$124.60 - 65.37$$. Step: $$124.60 - 65.37 = 59.23$$. 5. Problem 15: Calculate $$246.00 - 163.80$$. Step: $$246.00 - 163.80 = 82.20$$. 6. Problem 16: Calculate $$589.60 - 146.97$$. Step: $$589.60 - 146.97 = 442.63$$. 7. Problem 17: Calculate $$184.00 - 39.75$$. Step: $$184.00 - 39.75 = 144.25$$. 8. Problem 18: Calculate $$760.00 - 394.86$$. Step: $$760.00 - 394.86 = 365.14$$. 9. Problem 19: Calculate $$1000.00 - 56.47$$. Step: $$1000.00 - 56.47 = 943.53$$. 10. Problem 20: Calculate $$2000.00 - 1865.93$$. Step: $$2000.00 - 1865.93 = 134.07$$. All these are simple vertical subtractions where you subtract the bottom number from the top. First, align decimals if present, subtract the digits column-wise, and borrow if necessary. Ensure to keep decimal points lined up for currency calculations for accurate subtraction.