Answer:
The number that rounds to 10,000 when rounded to the nearest ten thousand and to 6,000 when rounded to the nearest thousand is 7,500.
When 7,500 is rounded to the nearest ten thousand, the result is 10,000 because the ten thousand digit is 1 and the rounding digit (the thousands digit) is 5, which is greater than or equal to 5.
When 7,500 is rounded to the nearest thousand, the result is 6,000 because the rounding digit (the hundreds digit) is 5, which rounds up the tens digit to 0 and changes the thousands digit to 6.