Shortcut to find percentage of a number within seconds
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| 21% of 250 | ||
| Step 1:21% can be split into 10%+10%+1% | ||
| Step 2:First we find 10% of 250 by shifting the decimal point to the left by one place we get, 10% of 250=25.0 | ||
| Step 3:Another 10% of 250 we get 10% of 250=25.0 | ||
| Step 4:Now we need to find 1% of 250 by shifting the decimal point to the left by 2 places. We get, 1% of 250=2.50 | ||
| Step 5:Adding all the results we get, 10%+10%+1%=25+25+2.50=52.50 | ||
MULTIPLICATION OF 125, 25, 5 WITH ANY NUMBER
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| 1. 93*125 = 93000/8 = 11625. | ||
| 2. 137*125 = 137000/8 = 17125 | ||
| 1. 67*25 = 6700/4 = 1675. | ||
| 2. 298*25 = 29800/4 = 7450. | ||
| 1. 49*5 = 490/2 = 245. | ||
| 453*5 = 4530/2 = 2265. | ||
| Finding Squares of numbers near to 10's | ||
| To find the squares of numbers near numbers of which squares are known | ||
| 422 | Add 40+41 to 402 =1681 | |
| 592 | Subtract 602-(60+59) =3481 | |
| Finding Squares of any Two digit numbers | |
| Let us find the Square of 372 | Let us find the Square of 542 |
| = 3*10(37+7)+72 | = 5*10(54+4)+42 |
| = 30(44)+49 | = 50(58)+16 |
| = 1320+49 | = 2900+16 |
| = 1369 | = 2916 |
| Finding Squares of any Three digit numbers | |
| Let us find the Square of 7362 | Let us find the Square of 4562 |
| = 7*102(736+36)+ 3*10(36+6)+62 | = 4*102(456+56)+ 5*10(56+6)+62 |
| = 700(772)+30(42)+36 | = 400(512)+50(62)+36 |
| = 540400+1260+36 | = 204800+3100+36 |
| = 541696 | = 207936 |
| Finding Squares of any Four digit numbers | |
| Let us find the Square of 87582 | |
| = 8*103(8758+758)+ 7*102(758+58)+ 5*10(58+8)+82 | |
| = 8000(9516)+700(816)+50(66)+64 | |
| = 76128000+571200+3300+64 | |
| = 76702564 | |