# Number sense

“Damn, these things are quite hard”
~ Oscar Wilde on Number Sense Tests

For those without comedic tastes, the self-proclaimed experts at Wikipedia have an article about Number sense.

Number sense is a contest sponsored by UIL representatives somewhere down in Texas. It is a mathematical contest in which all participants must use their brain to solve 80 questions mentally in 10 minutes. It often causes SEHS.

There are two variations of the Number sense contest. The first, and most common, allows participants to write down answers without using any scratch work or calculators of any kind. The second, however, does not allow to participant to use a pencil, instead further enhancing mental abilities by forcing participants to telepathically transmit their answers to their paper.

## editCompetition Details

Students are trapped in a room, most commonly a high school room (though sometimes college), with a proctor. The tests are handed out to the students, face down. Any student that looks at the test before hand will be disqualified (or in rare occasions, murdered). When the proctor says "Go" or "Start the fucking test," the students are allowed to look at the tests and begin working all the problems. They are to be timed for 10 minutes and no scratch work, marking over wrong answers, or erasing wrong answers is not allowed. For every problem answered correctly, you are awarded five points; for every problem skipped or answered incorrectly, four points are deducted from your score. It is impossible to score a perfect score unless you are God. In fact, anything over 300 at least warrants Deity status.

## editProblems Typically Seen on a Test

The difficulty of the problems vary from test to test, ranging from stupid easy to impossible. Examples are:

• $2+2=$
• $2*3=$
• The $f(x)$ is defined as $ln(x*52/17)+C$ where C is some arbitrary constant. If the $f(6)=7.1538$, then the $f(e)$(rounded to 4 decimal places) is _______

As you can see, for the most part the problems are quite difficult (especially the first two examples). However, there are short cuts typically found for each problems.

### editExample 1

• $2+2$

By using the Identity Property of Addition we are able to separate the problem:

• $1+1+1+1$

From here, we can take advantage of the Distribution Property and manipulate it further to get:

• $1*(1+1+1+1)$

We can then simplify the inside of the brackets:

• $1*(4)$

We can then recognize that $4= 2^2$ and substitute:

• $1*(2^2)$

Spreading out all the factors and taking away the brackets leaves us:

• $1*2*2$

You can then derive the answer using simple multiplication and fill it in the answer blank, which looks like this:

• $2+2=73$

### editExample 2

• $2*3$

This is commonly referred to as the Three's Trick. To first tackle this problem, one must first realize that $3=6/2$. We can then substitute it into the equation, like so:

• $2*6/2$

You then can notice the $2$s cancel out, leaving you with:

• $2*3=6$

### editExample 3

Example 3 is usually considered one of the easier problems on the test (and they show up frequently). Simple math is all that is required to derive that: $f(e)= 6.3620$

## editPracticing

Though in most cases you will be unable to score higher than a 8, if you are determined enough you can break double digits. The most common study habits are to take 5 number sense practice tests every 7 minutes. This is obtained by concentrating so hard, you actually create a time warp causing yourself to relive the same 7 minutes numerous times. The only people to have ever been noted to use this study method are God and Oscar Wilde. Even though there have been other study patterns developed over the years, they've all been discovered to be completely worthless.