2. \( 78-35=78-35= \) 3. \( 125+64=125+64= \) 4. \( 200-89=200-89= \) 5. \( 567+198=567+198= \) 6. \( 430-275=430-275= \) 7. \( 950+105=950+105= \) 8. \( 600-327=600-327= \) 9. \( 1.240+3.560=1.240+3.560= \) 10. \( 4.000-1.875=4.000-1.875= \)

Did you know that subtraction and addition are some of the most fundamental arithmetic operations? Their origins can be traced back to ancient civilizations, where counting objects was a common necessity. The Babylonians used a base-60 number system, which still influences how we measure time today! In a practical sense, mastering these basic operations can be a game changer, whether you're managing your finances, cooking up a storm in the kitchen, or just trying to solve everyday puzzles. Remember to double-check your calculations; a simple slip can lead to an entirely different conclusion. Always use estimation to keep your answers reasonable!