Answer :
To estimate the differences to the nearest ten thousand, we first round each number to the nearest ten thousand and then subtract.\n\nLet's go through each problem step by step:\n\n1. 76,539 - 69,778\n\n - Round 76,539 to the nearest ten thousand: 80,000.\n - Round 69,778 to the nearest ten thousand: 70,000.\n - Estimated difference: 80,000 - 70,000 = 10,000.\n\n2. 64,832 - 39,498\n\n - Round 64,832 to the nearest ten thousand: 60,000.\n - Round 39,498 to the nearest ten thousand: 40,000.\n - Estimated difference: 60,000 - 40,000 = 20,000.\n\n3. 83,453 - 29,876\n\n - Round 83,453 to the nearest ten thousand: 80,000.\n - Round 29,876 to the nearest ten thousand: 30,000.\n - Estimated difference: 80,000 - 30,000 = 50,000.\n\n4. 957,932 - 843,621\n\n - Round 957,932 to the nearest ten thousand: 960,000.\n - Round 843,621 to the nearest ten thousand: 840,000.\n - Estimated difference: 960,000 - 840,000 = 120,000.\n\n5. 576,689 - 253,456\n\n - Round 576,689 to the nearest ten thousand: 580,000.\n - Round 253,456 to the nearest ten thousand: 250,000.\n - Estimated difference: 580,000 - 250,000 = 330,000.\n\n6. 487,699 - 253,456\n\n - Round 487,699 to the nearest ten thousand: 490,000.\n - Round 253,456 to the nearest ten thousand: 250,000.\n - Estimated difference: 490,000 - 250,000 = 240,000.\n\nThis exercise helps reinforce rounding skills and provides practice in basic subtraction using estimated values. When you estimate, the final result gives you a ballpark figure that is close to the exact answer, which is useful for quick calculations.
