While there are buttons to do this, fractions are much easier to type in manually. The reason is that most scientific calculators only output in decimal format.  For example, to evaluate 4/5 + 6/7, type in 4÷5+6÷7={\displaystyle 4\div 5+6\div 7=} to get approximately 1.657. Use parentheses for more complex operations. To convert back to fractions, use 2nd PRB{\displaystyle \mathrm {2nd} \ \mathrm {PRB} } to get the answer in mixed fractions. Do this using the x2{\displaystyle x^{2}} button. Type in the number you want to square, then hit the that button.  For example, to square the number 12, type 12 x2={\displaystyle 12\ x^{2}=}. To find powers of any number, use the ∧{\displaystyle \wedge } key. For example, type 3∧5={\displaystyle 3\wedge 5=} to get 243. Type 2nd x2{\displaystyle \mathrm {2nd} \ x^{2}} to display the square root. To find the square root of 9, type 2nd x2 9={\displaystyle \mathrm {2nd} \ x^{2}\ 9=}. There are two buttons for logarithms. The LOG{\displaystyle \mathrm {LOG} } is the logarithm base 10. Use whichever one is appropriate. For example, to find the logarithm base 10 of 100, simply type LOG 100={\displaystyle \mathrm {LOG} \ 100=}. The exponential function ex{\displaystyle e^{x}} is found by typing 2nd LN{\displaystyle \mathrm {2nd} \ \mathrm {LN} }. If you need to use Euler's number only, use e to the first power. For example, to find the natural log of e, type in LN 2nd LN 1={\displaystyle \mathrm {LN} \ \mathrm {2nd} \ \mathrm {LN} \ 1=}. Sine, cosine, and tangent come standard with any scientific calculator. To use these buttons, be sure that you know whether to use degrees or radians. To convert, use the DRG{\displaystyle \mathrm {DRG} } button to highlight DEG or RAD. Other calculators will generally have a button that converts between these two systems. For example, if you wanted to find the sine of 60 degrees, make sure that you are in degree mode by checking the lower right of the display. Then, type SIN 60={\displaystyle \mathrm {SIN} \ 60=}. Do this using the x−1{\displaystyle x^{-1}} button. On some calculators, it may be labeled as 1/x{\displaystyle 1/x} instead. Type in the number you want to find the reciprocal of, then hit the reciprocal button. For example, to find the reciprocal of 3, type 3 x−1={\displaystyle 3\ x^{-1}=}.
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One-sentence summary -- Make a fraction. Square a number. Find a square root. Find logarithms. Use the exponential function. Find trigonometric functions. Find the reciprocal of a number.


The burning sensation that you feel creeping up from your stomach into your throat after or during meals is heartburn. If you eat overly large meals or if you lay down right after eating, then you may be encouraging heartburn. Belching often accompanies heartburn as a sign of general digestive upset. Mylanta Gas and Gas-X are 2 of the more commonly available remedies. They help to dissolve and break apart any gas bubbles that make their way into your digestive system. Similar products, such as Beano, target the gas produced by particular foods. Many of these OTC medications also treat general flatulence as well. If you start to experience regular or extreme pain in your stomach or abdomen, then this could be a sign of a serious digestive problem. Loose or bloody stools can indicate the same thing. If you start to lose weight quickly, then the burping may be a sign that your body isn’t processing food correctly. Similarly, heartburn can cause mild pain in the chest area. But, it should never become extremely painful or radiating. Gastroesophageal reflux disease (GERD) causes inflammation in the lining of the intestines and can result in excessive belching. To diagnose GERD, your doctor might slide a small, flexible camera tube down your throat to examine your digestive system. GERD can also cause heartburn and ulcers in the intestines.
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One-sentence summary --
Don’t lie down right after eating. Take an over-the-counter antacid containing simethicone. Reach out to your doctor if your symptoms worsen. Get an endoscopy to rule out the possibility of GERD.