Exercises: multiplying decimal numbers

Introduce a variable $x$ that corresponds to the number by which $0.0123$ must be multiplied to obtain $1230$.

Then, set up the equation:

Introduce a variable $x$ that corresponds to the number by which $0.0123$ must be divided to obtain $0.123$.

Then, set up the equation:

Introduce a variable $x$ that corresponds to the number by which $0.0123$ must be divided to obtain $1000$.

Then, set up the equation:

If we multiply any number $x$ by $0.01$, it looks like this:

$\phantom{=.}x\cdot 0.01$

$=x\cdot \frac{1}{100}$

$=x:100$

You only have to move the decimal point two positions to the left inside the number $x$, as you divide by 100.

Example: $13.7\cdot 0.01$

$\phantom{Bei.:}=13.7:100$

$\phantom{Bei.:}=0.137$

If we divide any number $x$ by $0.01$, it looks like this:

$x:0.01$

$=x:\frac{1}{100}$

$=x\cdot 100$

You only have to move the decimal point two positions to the right inside the number $x$, as you multiply by 100.

Example: $13.7:0.01$

$\phantom{Bei.:}=13.7\cdot 100$

$\phantom{Bei.:}=1370$