cm to inches | with fraction
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5 سال پیش
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In this video I demonstrate
In this video I demonstrate how to convert cm to inches. In fact I present two methods that can be both useful, depending on the circumstances. One method that you can use when you have the luxury of a calculator or you need accuracy. And another method that you can use when a calculator is unavailable or you need only a quick approximation.
The accurate conversion rule from cm to inches is defined by this equation:
1 inch = 2.54 cm.
Knowing this, it is rather trivial to convert from inches to cm. Simply, multiply with 2.54. For example: 4 inches are converted to 4 * 2.54 = 10.16 cm.
For the opposite conversion that is, to get inches from cm, we must do the reverse operation. Reverse of multiplication is division, so we must divide cm by 2.54. For example, 11 cm are converted to 11 / 2.54 = 4.33 inches. If you need the fraction too, you can find it this way: lets say you need the fraction in 64ths of an inch. In other words, you must find how many 64ths make 0.33…
X/64 = 0.33
Solving for x,we find x must be 64*0.33 = 21.12 which is rounded to 21 (the nearest integer). So the fraction is 21 over 64 and the final answer is that 11 cm are converted to 4 21/64 inches.
That was the accurate method. It requires a calculator, because you need to divide by 2.54 which for most people is a hard operation to perform manually.
Now lets see the second method which is slightly less accurate but can be used without a calculator. The conversion rule is again 1 inch = 2.54 cm. If we round it to 1 inch = 2.5 cm, we introduce a small error but now, we find out that 4 inches are 10 cm exactly. Or, that 1 cm = 4/10 of an inch which is very convenient. We use a trick: instead of dividing by 2.5, we multiply cm with 4 and then divide by 10, which is equivalent mathematically, but these two operations are far more easy to do manually, compared to division. Let’s apply this to an example… if we have say 22 cm, and we need to convert to inches, first, we multiply with 4, which gives 88, then divide by 10, and finally get 8.8 inches. The accurate conversion in comparison gives 8.66 inches. If you are in hurry, or you smartphone is out of battery, this is a quite good approximation.
Please, ask any questions in the comments section and if you liked the video, subscribe.
Attribution to free images used in the video:
https://pixabay.com/users/OpenClipart...
https://www.maxpixel.net/Site-Calcula...
https://pixabay.com/users/geralt-9301...
The accurate conversion rule from cm to inches is defined by this equation:
1 inch = 2.54 cm.
Knowing this, it is rather trivial to convert from inches to cm. Simply, multiply with 2.54. For example: 4 inches are converted to 4 * 2.54 = 10.16 cm.
For the opposite conversion that is, to get inches from cm, we must do the reverse operation. Reverse of multiplication is division, so we must divide cm by 2.54. For example, 11 cm are converted to 11 / 2.54 = 4.33 inches. If you need the fraction too, you can find it this way: lets say you need the fraction in 64ths of an inch. In other words, you must find how many 64ths make 0.33…
X/64 = 0.33
Solving for x,we find x must be 64*0.33 = 21.12 which is rounded to 21 (the nearest integer). So the fraction is 21 over 64 and the final answer is that 11 cm are converted to 4 21/64 inches.
That was the accurate method. It requires a calculator, because you need to divide by 2.54 which for most people is a hard operation to perform manually.
Now lets see the second method which is slightly less accurate but can be used without a calculator. The conversion rule is again 1 inch = 2.54 cm. If we round it to 1 inch = 2.5 cm, we introduce a small error but now, we find out that 4 inches are 10 cm exactly. Or, that 1 cm = 4/10 of an inch which is very convenient. We use a trick: instead of dividing by 2.5, we multiply cm with 4 and then divide by 10, which is equivalent mathematically, but these two operations are far more easy to do manually, compared to division. Let’s apply this to an example… if we have say 22 cm, and we need to convert to inches, first, we multiply with 4, which gives 88, then divide by 10, and finally get 8.8 inches. The accurate conversion in comparison gives 8.66 inches. If you are in hurry, or you smartphone is out of battery, this is a quite good approximation.
Please, ask any questions in the comments section and if you liked the video, subscribe.
Attribution to free images used in the video:
https://pixabay.com/users/OpenClipart...
https://www.maxpixel.net/Site-Calcula...
https://pixabay.com/users/geralt-9301...
5 سال پیش
در تاریخ 1398/01/12 منتشر شده
است.
174
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