Problem: Article: The easiest way to identify your range is with the assistance of a tuned instrument that you can play while you sing, like a piano or keyboard. If you do not have access to the physical instrument, download a piano app, such as Virtual Piano, on your smartphone, tablet, or other device as a substitute. Using an online piano on your laptop or device will give you access to a full simulated keyboard. It will also make it much easier to figure out which notes are your highest and lowest because the app will actually indicate the correct scientific pitch notation for a key as you play it. Start by figuring out what the bottom end of your natural range is by locating the lowest note that you can sing comfortably without your voice croaking or cracking. You should also not have to “breathe” the note; that is, its tone quality should match that of the rest of your chest voice and not have a breathy or scratchy sound.  Instead of trying to pull your lowest note out of thin air, start by singing a higher note on a consistent vowel sound (like “ah” or “ee” or “oo”) and work your way down the scale into your lowest registers. If you’re a woman, start with an easy C4 (middle C on the piano), and work your way down the keys, matching each note until you hit your lowest. If you’re a man, play a C3 on the piano, and go down one key at a time from there. The goal is to find the lowest note you can still sing comfortably, so do not count notes that you cannot sustain. Once you know how far down your voice can reach comfortably, try to go a bit lower, key by key and note by note. Breathy notes that you can sustain count here, but croaky notes that you cannot hold do not. For some singers their normal and breathy lowest notes may coincide. For others, they might not. Once you have found your lowest normal-voiced note and the lowest one you can reach, write them down. Do so by identifying the piano key that corresponds to the note and then figuring out its correct scientific pitch notation. For example, if the lowest note you can hit as you descend the scale is the second-to-last E on the keyboard, then you’d write down E2.
Summary: Locate a piano-like instrument. Find the lowest note you can sing in your normal (modal) voice. Sing the lowest note you can, including breathing. Record your lowest notes.

INPUT ARTICLE: Article: Your sick baby may not want to eat as much, but if their appetite hasn't changed, avoid feeding them as much as they normally eat. Feeding smaller, more frequent meals is gentler on their sensitive stomachs and they'll be less likely to vomit it up. To help you monitor your baby's illness, you might want to write down when you feed the baby and about how much they ate or how long they nursed. Then, make a note if they keep it down or vomit shortly after. Watch for when your baby pauses during a feed and use the opportunity to burp them. Try to do this 2 to 3 times while they eat and spend less than 1 minute burping, stopping even if they haven't burped. If your baby hasn't burped after you've tried burping them for 1 minute, they probably don't have trapped gas to release so let them go back to feeding. Your sick baby might not enjoy the sensation of movement, which can make them feel nauseous. Instead of swinging or bouncing your baby, cradle them in your arms and hold them steady. Cuddling your sick baby can reassure them and make them feel more comfortable. If your sick baby seems gassy and unable to burp, put them into a baby bathtub that's half full of warm water. After the bath, dry your baby and lay them on their back. Then, use lotioned hands to gently rub across their tummy in a clockwise direction. The warm bath can relax their stomach muscles and the massage can release trapped air so the baby burps. If your baby swallows a lot of air during a feeding session, they may become gassy or have to burp a lot. To reduce discomfort, consider buying anti-colic bottles that are designed to make it easier for your baby to suck without swallowing a lot of air. You can also check the baby bottle nipples to ensure that milk isn't flowing too quickly, which can cause your baby to choke.

SUMMARY: Give your baby smaller feedings. Burp your sick baby 2 to 3 times during each feeding session. Avoid swinging or jiggling your baby. Give your baby a massage or bath to relax them. Adjust your baby's bottle to prevent them from swallowing air.

In one sentence, describe what the following article is about: The polarity of batteries is what helps them supply current to a device. The plus sign, or +, indicates the positive terminal. On AA, AAA, C, and D batteries, the positive end should be slightly raised. The negative end of the battery should be flat, and it may or may not be marked with a minus, or -, symbol. There should be a plus and minus sign inside the battery compartment. This will tell you which direction the battery needs to go. The negative end may have a spring or a small metal lever. If the polarity isn’t marked on your device, you may need to consult the manufacturer's instructions. It’s very important to make sure that each battery is properly aligned inside the device. If your battery faces the wrong way, it could cause your device to malfunction, or it could even cause the batteries to leak dangerous corrosive chemicals. The plus sign on the battery should match the plus sign on the device. As you insert the negative end of the battery, you may press down a spring or a lever. By installing the negative end first, the battery will slide into the compartment more easily. You should then be able to easily snap the positive end into place. The positive end of the battery should snap into place with a gentle push. If you have multiple batteries side-by-side, they may alternate directions. This creates a series of current that amplifies the energy produced by the batteries. Make sure each battery faces the direction that’s indicated in the battery compartment or the user manual. Some devices that use multiple batteries may continue to function if one battery is installed incorrectly, but you can damage the device or shorten the life of the batteries by doing so.
Summary:
Look for a plus symbol on your battery. Find the positive and negative symbols on your device. Align the symbols on the battery with those on your device. Slide the battery into place with the negative end first. Check the alignment of every battery.