In one sentence, describe what the following article is about: In a simple substitution cipher, you can assigning letter values to other letters. For example, A may equal C and and F might equal J. Make sure you don’t choose easy combinations like A = B or A = Z. They’ll be easily broken.  Make decoder rings. Those decoder rings you got in a box of cereal years ago may come in handy, but you can make your own too if you want. Write your letters, A through Z, in a large circle. Then, write the substituted letters inside the large circle to form their own smaller circle. Now you’ll have a key for your cipher. Randomize the cipher. Once you’ve got your keys and your friends have theirs too, you can cut out both rings from the paper. Turn the smaller ring inside the larger outer ring to create new substitutions. When you pass your note, write what A equals, and the reader will know where to set their rings. To make a slightly more complicated substitution cipher, you can make your own simple symbols to stand in for letters. The more each symbol looks different than the letter it represents, the harder the code will be to crack. Make sure each symbol is also simple and easy to draw quickly.  Create a key for your new language. Make a master key that shows which letter matches up with each symbol. As you practice writing in your new script, you’ll become more familiar with the symbols, but you’ll need a key at first to remember which is which. Share the key with friends. Your language won’t be of much use if only you can read the notes you pass! Share the key with your friends, advising them to keep it safe so that no one else finds and learns the symbols. Write your messages in the new language. Practice the symbols until you can read and write them as quickly as your native language. It’ll take a while, but you’ll get to know the symbols well over time. For example, swap A with (α) Alpha, B with (β) Beta, C with (Χ) Chi, etc. from the Greek alphabet..  Use similar characters for missing letters. Some foreign alphabets may not contain all the letters in your language. Greek doesn't have Y, but there's a visually similar Upsilon (Y in capitals), so you might use that instead. Make sure your reader knows that you’re going to be substituting some letters for others not in the language. Test some examples.  For example: "See you tonight" becomes "ΣΕΕ ΤΗΟΥ ΤΟΝΙΓΗΤ,” with “you” subbed out for “thou” because Greek doesn’t have a character for “Y”. Numbers tend to stick out in messages with a lot of text, so try to find a better way to to hide them in your cipher. For example, replace the "8" in "See you tonight, 8 o'clock" with "√(128/2)". The 8 is replaced by a simple math: the square root of (128/2=64)=8. It’s relatively easy to crack a substitution code, because you’re still using your native language and only swapping out the letters for other letters or symbols. Words like “and”, “you” and “the”, which will show up frequently in your messages, and can be found out and used to piece together parts of a key. Common letters like E, T and A also help code-breakers to decipher your message.
Summary: Substitute letters for other letters. Substitute your own symbols for letters. Substitute letters from another language. Substitute equations for numbers. Be aware that substitution ciphers can be broken.

This forms a roll of cloth, hiding the raw edges of both layers.
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One-sentence summary -- Insert the bag interior into the bag exterior. Clip the inner layer so that it’s 2 inches (5 cm) higher than the edge of your laptop (or box, in this case). Clip the outer layer two inches (5 cm) longer than the inner layer. Fold the outer layer twice – once in and over itself and once again over the inner layer – and pin for sewing.

Q: An unfilled hot tub can weigh upwards of 800 pounds (363 kg), so it's important to know how you will get it from the delivery van to your backyard. Make sure that the width of the tub will pass through any gates, foliage, or structures with enough leeway.  Some delivery drivers will help you with this step. If you find that the tub is bigger than certain obstacles in your path will allow, you may need to improvise. Cutting a branch or removing a part of a fence, although it appears drastic, is sometimes the only thing that you can do. The voltage of a hot tub is higher (usually around 240 volts) than regular home outlets, so you will need to install a breaker to your electrical control box. If you are not familiar with electrical systems, it is best to hire an electrician to assist you in this aspect of installation. See the section below for more information on electrical wiring and help. You're almost ready to start enjoying your brand new tub, without having broken the bank by paying someone else to install it. To complete the installation, you'll want to:  Turn off the electricity. Clean the interior of the hot tub and make sure all jets and knobs are in place. Open the air valves. Fill the hot tub with water from a garden hose or using buckets of water from inside. No special water is necessarily required. Turn the electricity back on and begin heating the tub. Mix in the proper chemicals to ensure sanitation.
A: Plan your delivery route of the tub from the curb to the foundation. Assemble the hot tub and hook up the electricity. Prepare the hot tub for use.

Article: Sometimes it may be hard to get into a book, even if you have a comfy spot, good lighting, and no distractions. If there aren’t any immediate time constraints, consider putting down the book and coming back to it at a later time. Try to choose a more relaxing time to revisit the book. For instance, you may find that you are better able to focus early in the morning, after working out, or when all your chores or tasks are done for the day. Your brain absorbs the unfolding of the story and information better when you read paper books. This is because you can observe the thickness of the book and use your body to interact with it (turning the pages, for example) while reading. If you prefer e-readers, that’s okay too! However, if you are struggling to understand books, try reading a paper one and take note of any changes that occur in your comprehension. When you get to the end of a chapter or section of a book, stop and ask yourself if you understand the major themes and events. If you recall what happened and have a good understanding, feel free to proceed. If you don’t, though, you should refresh your memory by going back over the previous pages, chapters, or sections. Keep a notebook next to you while you read. Use several different pieces of paper to keep track of main characters or key terms, major plot points, big-picture questions, and things that confuse you. You can refer to these notes later to remember what the book was about. This is especially helpful for academic texts. When reading a book for pleasure, however, frequently stopping can disrupt the flow of your reading. Talking about books is a great way to really understand them. Other people may notice things you didn’t, and vice versa. Talk to your friends or go to your local library to join or organize a club. You can also find book clubs and forums for discussion online.
Question: What is a summary of what this article is about?
Make sure you’re in the right frame of mind to focus. Pick paper books over e-readers for better understanding. Check your knowledge of what has happened before moving onto a new section. Take good notes while you read. Join a book club to have group discussions.

Problem: Article: This technique creates a wood grain appearance.
Summary:
Apply your base coat to the wall and then a glaze. Choose a comb with the desired tooth size and, starting at the top, comb through the glaze.