When measuring some property of an object the number we measure depends on the units chosen. For example, 1cm = 0.01m, so converting from cm to m makes the number get smaller; we need more small units to make up the number of big units. In each case below, does the number get bigger or smaller following a change in units? Can you estimate without a calculator an approximate factor by which the numbers would change in each case?

1 cm ²Ž ?? m ²
1 foot Ž ?? inches
1 mile Ž ?? kilometers
1 litre Ž ?? cm ³
1 foot ³Ž ?? inches ³
1 m s ^-1Ž ?? miles / hour
1 mm ³Ž ?? m ³
1 degrees C Ž ?? degrees K
85 degrees Ž ?? radians
1 Pa Ž ?? cm^-1 g s^-2
1 W Ž ?? cm² g s^-2
1 Hz Ž ?? per minute
1 Mol Ž ?? trillion
Molarity of 1Ž ?? per cm³
1 katal Ž ?? million million per picosecond

Can you make up some of your own similar problems?

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