From Förberedande kurs i matematik 1

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-	{{NAVCONTENT_START}}	+	Instead of always going back to the definition of the logarithm, it is better to learn to work with the log laws,
-	<center> [[Bild:3_3_2f.gif]] </center>	+
-	{{NAVCONTENT_STOP}}	+	:*<math>\ \lg (ab) = \lg a + \lg b</math>
		+
		+	:*<math>\ \lg a^{b} = b\lg a</math>
		+
		+	and to simplify expressions first. By working in this way, one only needs, in principle, to learn that <math>\lg 10 = 1\,</math>.
		+
		+	In our case, we have
		+
		+	{{Displayed math||<math>\lg 10^{3} = 3\cdot \lg 10 = 3\cdot 1 = 3\,\textrm{.}</math>}}

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Current revision

Instead of always going back to the definition of the logarithm, it is better to learn to work with the log laws,

• \displaystyle \ \lg (ab) = \lg a + \lg b

• \displaystyle \ \lg a^{b} = b\lg a

and to simplify expressions first. By working in this way, one only needs, in principle, to learn that \displaystyle \lg 10 = 1\,.

In our case, we have

\displaystyle \lg 10^{3} = 3\cdot \lg 10 = 3\cdot 1 = 3\,\textrm{.}