Question 969523
As a fraction, Tim planted {{{45/106}}} of the trees.
WE cannot simplify that fraction,
and we cannot write it as a fraction with a {{{100}}} for a denominator.
However, we can write a ratio, with a {{{100}}} for a denominator,
that is approximately equal to {{{45/106}}} .
If you divide {{{45}}} by {{{106}}} , you get {{{45/106="0.42452830186679..."}}} .
The digits will eventually repeat, but it may take up to 105 digits before we see a repetition.
I would just approximate it as
{{{45/106=about0.42453=0.42453*100/100=42.453/100}}} .
That means that for every {{{100}}} trees that were to be planted,
Tim planted about {{{42.453}}} trees,
and that is the approximate percentage, {{{"42.453%"}}} .
To calculate a percentage,
you just divide to get the ratio as a decimal,
and then multiply times {{{100}}} .
which rounds to {{{highlight(42)}}} ,
because {{{42}}} is closer to {{{42.453}}} than {{{43}}} .
So, we say that Tim planted {{{highlight("42%")}}} of the trees called for in the project.
 
NOTES:
A percentage is a ratio, which is sort-of a fraction.
If Joe had planted {{{85}}} out of {{{200}}} trees in a project,
he would have planted {{{85/200=0.425=42.5/100=425/1000}}} .
The fractions {{{85/200}}} and {{{425/1000}}} are equivalent fractions.
We cannot call {{{42.5/100}}} a fraction; we call it a ratio,
and we say that the ratios
{{{85/200}}} , {{{42.5/100}}} , and {{{425/1000}}} are the same. 
They are equal, they are equivalent.
In that case we would say that {{{85}}} out of {{{200}}} is {{{"42.5%"}}} ,
and if we had to round ti whole numbers, we would sat it's {{{"43%"}}} ,
because {{{42.5}}} is a s close to {{{42}}} as it is to {{{43}}} ,
but the usual custom is to always round up in those cases.
{if you have to get rid of a bunch of digits to round,
you look art the first digit you are discarding.
If it is 5 or more , you round up,
otherwise you round down>
So, {{{42.3251}}} rounds down to {{{42}}} , but {{{42.5}}} , {{{42.50112}}} and {{{42.637}}} round up to {{{43}}} .
(If the first digit after the decimal point is not 5 or more,
you just get rid of all digits after the decimal point,
and leave the {{{42}}} as is.
Otherwise you up the {{{42}}} to {{{43}}} ).