Multiplying two 2-digit numbers (same 2nd digit) 1. Both numbers should have the same second digit. 2. Choose first digits whose sum is 10. 3. Multiply the first digits and add one second: X X _ _. 4. Multiply the second digits together: _ _ X X. Example: 1. If the first number is 67, choose 47 as the second number (same second digit, first digits add to 10). 2. Multiply the 1st digits, add one 2nd. 6x4 = 24, 24+7 = 31. 3 1 _ _ 3. Multiply the 2nd digits. 7x7 = 49 _ _ 4 9 4. So 67 × 47 = 3149. See the pattern? 1. If the first number is 93, choose 13 as the second number (same second digit, first digits add to 10). 2. Multiply the 1st digits, add one 2nd. 9x1 = 9, 9+3 = 12. 1 2 _ _ 3. Multiply the 2nd digits. 3x3 = 9 _ _ 0 9 4. So 93 × 13 = 1209....
Multiplying two 2-digit- Perkalian 2 Digit
Multiplying two 2-digit numbers(same 1st digit) 1. Select two 2-digit numbers with the same first digit. 2. Multiply their second digits (keep the carry). _ _ _ X 3. Multiply the sum of the second digits by the first digit, add the carry (keep the carry). _ _ X _ 4. Multiply the first digits (add the carry). X X _ _ Example: 1. If the first number is 42, choose 45 as the second number (any 2-digit number with first digit 4). 2. Multiply the last digits: 2 × 5 = 10 (keep carry) _ _ _ 0 3. Multiply the sum of the 2nd digits by the first: 5 + 2 = 7; 7 × 4 = 28; 28 + 1 = 29 (keep carry) _ _ 9 _ 4. Multiply the first digits (add the carry) 4 × 4 = 16; 16 + 2 = 18 1 8 _ _ 5. So 42 × 45 = 1890. See the pattern?...
Squares Trick - Trick Menghitung Pangkat
1. Squares of numbers from 26 through 50. Let A be such a number. Subtract 25 from A to get x. Subtract x from 25 to get, say, a. Then A2 = a2 + 100x. For example, if A = 26, then x = 1 and 1375/5 = 2750/10 = 275. Hence 262 = 242 + 100 = 676. Similarly, if A = 37, then x = 37 - 25 = 12, and a = 25 - 12 = 13. Therefore, 372 = 132 + 100·12 = 1200 + 169 = 1369. Why does this work? (25 + x)2 - (25 - x)2=[(25 + x) + (25 - x)]·[(25 + x) - (25 - x)] = 50·2x = 100x.2. Squares of numbers from 51 through 99. The idea is the same as above. (50 + x)2 - (50 - x)2 = 100·2x = 200x. For example, 32 = 372 + 200·13 = 1369 + 2600 = 3969.3. Squares of numbers from 51 through 99, second approach (this one was communicated to me by my late father...
Mathematics Trick
1. Multiplication by 5It's often more convenient instead of multiplying by 5 to multiply first by 10 and then divide by 2.For example, 137·5 = 1370/2 = 685.2. Division by 5Similarly, it's often more convenient instead to multiply first by 2 and then divide by 10.For example, 1375/5 = 2750/10 = 275.3.Division/multiplication by 4Replace either with a repeated operation by 2.For example, 124/4 = 62/2 = 31. Also,124·4 = 248·2 = 496.4.Division/multiplication by 25Use operations with 4 instead.For example, 37·25 = 3700/4 = 1850/2 = 925.5.Division/multiplication by 8Replace either with a repeated operation by 2.For example, 124·8 = 248·4 = 496·2 = 992.6.Division/multiplication by 125Use operations with 8 instead.For example, 37·125 = 37000/8 = 18500/4 = 9250/2 = 46...
Integral Basic Formula
This formula and table of integral only a basic function and simple product of e, sin x and cos xrumus yang ada di halaman ini hanya memuat rumus dasar dan rumus dasar untuk nilai e, sin x dan cos x1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12....
Mathematics Constants
A mathematical constant is a quantity, usually a real number or a complex number, that arises naturally in mathematics and does not change. Unlike physical constants, mathematical constants are defined independently of any physical measurementthere is some of Mathematics Constants PhiDefinition :The constant p (Greek letter pi) is, classically, defined as the ratio of the circumference p of a circle to its diameter d:p = pd = 2prand, as proved by Archimedes of Syracuse (287-212 BC) in his famous Measurement of a Circle, the same constant is also the ratio of the area A enclosed by the circle to the square of its radius r:A = pr2.or phi = 3.14159265358979323846264338327950288419716939937510E...