## Math and Science

5/23/2013

Math and science are connect in one main way. In complex science, math is used to test theories and hypotheses. Since much of science is theoretical and cannot yet be tested in the real world, math plays a big role. For example, Einstein's theories were in the category of physical science. But his arguably most famous contribution, the equation E=MC^2, is nothing more than variables and exponents that have real life counterparts. Isaac Newton, who developed the theory of gravity and the three laws of motion, also created a complex form of math known as calculus, which he used to help him in his work.

Much of math is learned ultimately for science. After years of test-taking and busy work, many of the math concept can be used in everyday science. From balancing an equation; for example, accurately doubling a recipe; to using a radical equation to find the perimeter of your fence, math plays a big part. Math is used in business, to measure profits, debts, and income. As can be seen, math is used in many things, even more than mentioned here.

## Negative Numbers

5/23/2013

Negative numbers are used a lot in higher level math, but they also appear in the real world. One way they can appear is in finances. For example, if someone owes someone else five dollars, they can be said to possess negative five dollars (\$-5). Negatives can also be used to combine debts, or be used in addition with positives to eliminate them. If someone owes five dollars and borrows five more, then the expression -5+(-5) can be used to find the overall debt of -10 dollars. If someone owes -5 dollars and earns 20 dollars, the expression -5+20 can be used to find the amount of money the person has with all debts paid.

Negatives are also present in the stock market, where they shows the rise or fall of the value of the stocks. If a stock has a difference from the previous day of -\$5, the it has fallen five dollars in value. If it has a difference of +\$5, then it has risen five dollars. Negatives can be used along with positives to show margin of error. If efficiency rating is 5.6 +/-.5, then the efficiency can go anywhere from 5.1 to 6.1. If the rating of another system is 6.6 +/-.7, then the rating can go anywhere from 5.9 to 7.3. It is possible for the first macine to be more

## 2x-7=15

5/23/2013

When solving an equation such as the one above, the ultimate goal is to isolate the variable. That is, to get the variable all alone on one side of the equal sign. This is necessary to solve the equation because solving the equation means knowing the value of x. Currently the value of 2x-7 is known, but that's not the correct answer because it's not simplified. Another important fact is to remember that any operation can be done, but it must be done to the equation as a whole, not to just one side. Combining "isolating the variable" and "both sides of the equation" will provide a clear path to finding the solution.

The first step in isolating the variable is to add 7, so the -7 is gone, and there is less on the side of the variable. However, this must be done to both sides. The result is 2x=22. Now the x side only has one more thing on it: 2x, or 2 times x. To undo multiplication, you divide. 2x/2 is x; and 22/2 is 11. The equation is now x=11.

## Decimal to a fraction

5/22/2013

One way to convert a decimal to a fraction has many steps. The first step is to count the number of places after the decimal. For example, .002 has 3. The next step is to put the digits over a number that starts with a one, and then has as many zeros as the decimal has place numbers. For example, 002/1000 or 2/1000. The final step is to simplify the fraction. For example, 2/1000 is 1/500. That is one way to convert decimals into fractions.

Another way is this. Multiply the decimal by ten until it isn't a decimal anymore. For example, .216*10=2.16; 2.16*10=21.6; 21.6*10=216. Then multiply the number of 10's together. For example, 10*10*10=1000. Put the non-decimal over the product of the tens: 216/1000. Now simplify. 108/500, 54/250, 27/125. The answer is 27/125. Those are two ways to transform decimals into fractions. They are both wim

## JJ s.

These are requests given by the Computech math teachers that I respond to every Monday.