Answer:
- 7040 yards
- zeros are place holders
Explanation:
Each mile is 1760 yards, so 4 of them is ...
4 × 1760 yards = 7040 yards
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This number is written as a decimal number in a "place value" system, so the position of the digit in the number tells its value.
In order for the 7 to indicate 7 thousand, it needs to be in the "thousands" place in the number. The 0s in the hundreds and units places are called "place holders" because they ensure the other digits appear in their proper places in the number.
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If it were written in Roman Numerals, it would be
. In this system, the letter tells its value (and "place" comes into account in XL, which means X is subtracted from L). The system of Roman Numerals has no zeros, and doesn't need them.