In one sentence, describe what the following article is about:

Sometimes, the scale needs to be zeroed out to be accurate. This can be done in two ways, depending on the scale you have. If you have an analog scale, press down on the scale with your hand and then lift up. The dial should level out to zero.  If it doesn't, use the turn wheel, usually located at the bottom of the scale or near the dial, to move the dial of the scale to zero while it's resting. Test it again to ensure it is at the right place. If you have a digital scale, follow the same procedure as with an analog except the balancing will be done with a digital button instead of a turn wheel. One way to check the accuracy of your bathroom scale is to test an object that you already know the weight of. It needs to be large enough to register on your scale but small enough that you can carry it to the scale. Try something like a new, unopened bag of flour or sugar. These generally are five to ten pounds and should be a consistent weight.  The weight of the paper or plastic bag these things come in shouldn't mess with the weight. If the flour or sugar comes in a heavy sack or metal container, you won't get an accurate reading and you should try another object. You can also try hand weights. The weight of these objects will be written on the side. Test to see if they are the weight they say they are. Another way that a scale may be inaccurate is across multiple weigh ins. Take an object you know the weight of, such as a hand weight or bag of sugar. Place it on the scale and note the weight. Take the object off and let the scale return to zero. Place the object on the scale again. Note the weight again. Repeat this at least five times to make sure that the scale in consistent over multiple weigh ins. You can weigh the object more if you get inconsistent results. Just make sure you do it an odd number of times so you can't have split results. Another way to make sure that a scale is accurate is to check the weight of two objects together. This will typically give you a larger amount of pounds, which will help test the scale at a higher level. It will also test the accuracy of the scale with an uneven weight distribution, which can be helpful for when you weigh yourself, since sometimes you might not stand with your weight 100% balanced.  Place one object on the scale. Note the weight. Take it off and let the scale even back out. Place another object on the scale and note its weight. Take it off and let the scale even back out. Now, place the two objects on the scale together. Note the combined weight. Add together the weight of the objects and see if it matches the weight the scale told you of them together. If it matches, the scale is accurate. If it doesn't, try it again and see if it is off by the same number. If it is, it might be that your scale is always off by that amount. You can also try stepping on the scale alone, noting the weight, and then stepping on the scale with an object that weighs X amount of pounds, like a 5 pound dumbbell or a 1 pound bag of flour. Then, check to see if the weight goes up by the exact amount that you are holding. If it does, then the scale is accurate.  For example, if you step on the scale and it says 145, then it should go up to 150 when you step on again while holding a 5 pound dumbbell. A scale can be affected by the surface it sits on. The best surface for a scale is a hard surface such as a flat bathroom or kitchen floor. It may be cushioned too much by carpet or other soft surfaces, which can make the scale off balance and give you inaccurate readings. Weight an object or yourself in the location you have your scale. Clear the scale and then move it to a different, more stable location. Weigh the same object again. The object should weigh the same. If it doesn't, one of the locations is causing inaccurate readings. Do a test with an object of known weight to see which one is accurate. Try to keep the scale in the same place every day. This way, even if the scale is slightly off, you should be getting the same error each day. This means that any weight you gain or lose, despite the number not being exactly correct, will still be how much you have gained or lost since your starting point was always the same.

Summary:
Zero out the scale. Weigh a familiar object. Reweigh an object multiple times. Weigh two objects together. Weigh yourself while holding an object. Change the location of the scale.