Problem: Article: For example, 120 × 120 =  Count the total number of zeros on the end. (In this case, 2). Do the rest of the problem.  12 × 12 = 144 Append the number of zeros counted to the end of the number;   14400 You might then be able to use some of the techniques below.  For example: Instead of 14 × 6  break 14 down into 10 and 4, and multiply both by 6, then add them together...14 × 6 = = 6×(10 + 4) = (10 × 6) + (4 × 6) = 60 + 24 = 84. For example:  Instead of: 35 * 37 = ?  do this: 35 × (35 + 2) =  =  352 + (2 × 35) = 1225 + 70 = 1295 Using; 352 = ?  Ignoring the 5 on the end, multiple the number (3) by the next highest number (4).   3 × 4 = 12 Append 25 to the end of the number.  1225 Using 412 = ? and 392 = ?  Figure the square you already know.  402 = 1600 Decide if you need to add or subtract. You will add with a larger square and subtract with a smaller one. Add the original number that was squared to the next number to be squared.  40 + 41 = 81  40 + 39 = 79. Make the addition or subtraction.  1600 + 81 = 1,681  --->   412 = 1,681  1600 - 79 = 1,521   ---->   392 = 1,521  This only works for numbers one unit above or below the original. Using 39 × 51 = ?  Find the number that is equidistant of both numbers.  In this case, 45, which is 6 away from both numbers. Square that number.  452 = 2025 Square the distance the numbers are from the central number.  62 = 36 Subtract that number from the first square.  2025 - 36 = 1989  If you have taken algebra, the formula is expressed as:  51 × 39 = (45 + 6)×(45 - 6) = 452 -6 2( x + y )×( x - y ) = x2 - y2  For a more complete explanation, see How to How to easily solve math problems using difference of squares. Using 25 × 12 = ?  Multiply by 100 by appending two zeros to the end of the other (not 25) number.  25 × 12   1200 Divide by 4.  1200 ÷ 4 = 300  25 × 12 = 300 For more details, see How to Multiply by 25 in your head.
Summary: Manage numbers ending in 0 (zero). Use the distributive property of multiplication to convert difficult to multiply numbers to easy to multiply numbers. Square numbers ending in 5 (five). Square numbers one less or more than a square you already know. Simplify multiplication by using "Difference of Squares". Multiply by 25.

Problem: Article: Some countries will have extensive lists of things you must include in the letter, whereas other countries will not have any requirements. You should check with your country's visa office and ask if there are any requirements. For example, in Canada, you must include the following information about the person you are inviting to visit:  complete name date of birth address and telephone number the person's relationship to you the purpose of their trip how long the person intends to stay in Canada where the person will stay how the person will pay for things the date the person intends to leave Canada The purpose of the letter is to put your country's consulate at ease that your friend or family member isn't getting a tourist visa so that they can enter the country and never leave. Accordingly, you want to make sure that the consulate knows the person intends only to stay for a limited period of time.  Go through your country's requirements, if there are any. Make sure to include all required information. Be sure to use your own language. The sample language provided in this article is used for illustrative purposes only. Say what you want to say in your own words and don't worry about sounding “official.” You should open a blank word processing document. Set the font to a comfortable size and style. For example, Times New Roman 12 point works for many people, though you could choose something equally readable. Set up the letter like a standard business letter. If you don't know what a standard business letter looks like, then search online for a sample. At the top of the page, justified with the left-hand margin, you should insert your name and address. Include your full street address, not a P.O. Box number. You need to identify the people you are inviting to come visit. Tab two lines down from your address and then insert the address of the person who will be visiting you. Include name and full mailing address. Begin the letter informally. For example, you could write, “Dear Mom and Dad” or something similar. In some countries, you might have to address the letter to your immigration office. Check your country's requirements.
Summary: Get your country's requirements, if any. Outline what you want to say. Format the document. Insert your name and address. Insert your recipient's address. Add a salutation.

Problem: Article: You can also click the Desktop to switch to the Finder. Next, click Preferences.    The files will now show their file extensions.
Summary: Select a Finder window or open a new Finder window. Click the Finder menu. Click "Advanced" in the Finder Preferences window. Click the Show all filename extensions box to add a check. Close the Finder Preferences window. Open a new Finder window.

Problem: Article: Move your TV until it is safe on the ground. Clear off a flat spot for it and lay down a clean, soft tablecloth or bedsheet. It would be a shame to get this far only to scratch up the screen. You’ve managed to dismount and protect your TV so far, but part of the mount remains attached to it. Fortunately, this part is way easier than getting the TV down. No matter the shape of the mount piece, it’ll be attached by four screws. Without the TV, the other mount piece is an empty frame on your wall. If you choose to remove it, undo it the same way you did the rest of the mount. These screws shouldn’t provide much resistance, so undo them and slip the mount piece off the wall.
Summary:
Place the TV face-down. Unscrew the mount piece on the TV. Unscrew the mount piece on the wall.