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## Main Question or Discussion Point

When multiplying significant numbers do you round to the least number of significant digits? My textbook says that a problem such as 16.235 × 0.217 × 5 = 17.614975 would be rounded to 20 since twenty has only one significant digit like 5. But http://www.physics.uoguelph.ca/tutorials/sig_fig/SIG_dig.htm" [Broken] says:

So would a simple problem such as 3 × 1.1 equal 3.3, 3, or 4?Note that whole numbers have essentially an unlimited number of significant digits. As an example, if a hair dryer uses 1.2 kW of power, then 2 identical hairdryers use 2.4 kW:

1.2 kW {2 sig. dig.} ´ 2 {unlimited sig. dig.} = 2.4 kW {2 sig. dig.}

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