I think they do some rounding off. The 7.5 number I mentioned earlier is an
approximation. I think people doing sensitive measurements use a different
chart.
"Stephen M. Henning" wrote in message
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Here is another one:

1) A liter of water is one kilogram by definition.
2) One kilogram is 2.2 pounds.
3) A quart is 2 pounds.

4) Hence, a liter is 1.1 quarts.

Conversion charts say that a liter is 1.0566882607957349 quarts. Why
the difference?









The above includes many approximations. The real values are.

1) A liter of water is one kilogram by definition at 4C and 1 atmosphere
of pressure. But at 20C a liter of water is 0.9982 kilograms.
2) One kilogram is 2.2046 pounds.
3) A quart is 2 pounds approximately. Actually at 4C a quart of water
is 2.086 pounds. At 20C a quart of water is 2.082 pounds.

4) Hence, at 4C a liter is 1.0567 quarts and at 20C a liter is 1.0567
quarts. So the common measures we take for granted are about 5 % off.

"Stephen M. Henning" wrote...
Here is another one:

1) A liter of water is one kilogram by definition.
2) One kilogram is 2.2 pounds.
3) A quart is 2 pounds.

4) Hence, a liter is 1.1 quarts.

Conversion charts say that a liter is 1.0566882607957349 quarts. Why
the difference?


Conversion from mass to force is not exact and depends on conditions.
The same holds true for volume and force (or volume and mass). Water
volume changes (slightly) when temperature changes. For most of us
two or three significant digits is good enough.