Vedic Math MUTIPLICATION Using “Vertical and Crosswise” Multiplication of large numbers becomes easy when we use this sutra. We will explain it with an example. Step 1 Step 2 Step 3 Step 1: multiply the two digits on the right side Step 2: cross-multiply digits of both columns, and add together Step 3: multiply the two digits of the left side Example 1: 21 X 32 Step 1: 2 1 Step 2: X 3 2 Step 3: 6 7 2 Step 4: 1 x 2 = 2; write 2 for the right column 2 x 2= 4 3 x 1 = 3; add 3 + 4 = 7, for the middle column 2 x 3 = 6; write 6 for the left column Example 2: 72 X 56 Step 1: 7 2 Step 2: X 5 6 Step 3: 4 05312 Step 4: 2 x 6 = 12 write 2 and carry over 1 5 x 2 = 10 7 x 6 = 42 add both products = 52 + 1 = 53, carry 5 7 x 5 = 35 plus 5 carry over = 40, for the left column Exercise 6: Solve the following using the sutra “vertical and crosswise” 1) 24 x 56 2) 43 x 29 3) 76 x 24 4) 13 x 43 5) 23 x 75 6) 62 x 81 7) 19 x 25 8) 15 x 79 9) 32 x 65 10) 71 x 29 Vedic Math Three Digit Multiplication Vertical and crosswise sutra can be extended to any number of digits. Let’s first look at 3 digit multiplication. Step 1 Step 2 Step 3 Step 4 Step 5 Example 3: 123 X 645 1 2 3 Step 1: 3 x 5 = 15; write 5, carry 1 X 6 4 5 Step 2: 2x5=10 + 3x4=12; 10 + 12 = 22+1= 23, write 3 carry 2 719332315 Step 3: 1x5=5 + 6x3=18 + 2x4=8; 5+18+8 = 31+2=33, write 3 carry 3 Step 4: 4x1=4 + 6x2=12; 4 + 12 = 16 + 3 = 19, write 9 carry 1 Step 5: 6x1=6 + 1 = 7 Example 4: 214 X 23 2 1 4 Step 1: 4 x 3 = 1 2 X 0 2 3 Step 2: (3x1) + (4x2) = 3 + 8 = 11 + 1 = 12 4 9 12 12 Step 3: (3x2) + (4x0) + (1x2) = 8 + 1 = 9 Step 4: (2x2) + (1x0) = 4 Step 5: 2 x 0 = 0 Exercise 7: Solve the following using the sutra “vertical and crosswise” 1) 123 x 215 2) 236 x 213 3) 721 x 72 4) 281 x 19 5) 982 x 124 6) 724 x 362 7) 289 x 727 8) 473 x 67 9) 926 x 94 10) 836 x 492 Vedic Math Four Digit Multiplication Vertical and crosswise sutra can be extended to any number of digits. Let’s now look at 4 digit multiplication. This process can be extended to any number of digits Step 1 Step 2 6 Step 7 Step 3 Step 4 Step 5 Exercise 8: 1) 1023 x 2132 2) 3125 x 126 3) 5216 x 29 4) 27 x 3271 5) 521 x 6215 6) 5612 x 2135 7) 752 x 1920 8) 9210 x 28 9) 617 x 5611 10) 6403 x 45 Step Answers Exercise 6: 1) 1344 2) 1247 3) 1824 6) 5022 7) 475 8) 1185 4) 559 5) 1725 9) 2080 10) 2059 Exercise 7: 1) 26445 2) 50268 3) 51912 4) 5339 5) 121768 6) 262088 7) 210103 8) 31691 9) 87044 10) 411312 2) 393750 3) 151264 4) 88317 5) 3238015 8) 257880 9) 3461987 10) 288135 Exercise 8: 1) 2181036 6) 11981620 7) 1443840 Vedic Math More Multiplication Multiplication using compliments The “all from 9 and last from 10” sutra allows us to multiply large numbers that are close to a base easily. This also applies when numbers are near different bases. Example 5: 88 X 98 88 - 12 98 - 2 86 / 24 Example 6: 9 x 8 9 - 1 8 - 2 7 / 2 Example 7: 97 x 98 97 - 3 98 - 2 95 / 06 Both numbers are close to the base 100. We write the numbers under each other with compliments on right. the – sign is used because the numbers are below the base. The right side is obtained by multiplying the compliments. The left side by cross-subtraction (88-2 = 98 – 12 = 86) We use the base of 10. adding zeros on the right side For a base of 100 there must be 2 digits on the right side Example 8: 88 x 89 extra numbers on the right side 88 - 12 Base of 100 89 - 11 132 is a 3-digit number, so 1 is carried to the left side 77 / 132 78 / 32 Example 9: 67859 x 99998 multiplying very large numbers easily 67859 – 32141 Here the base is 100,000 99998 – 2 The compliment is easy to find using “all from 9 last from 10 67857 / 64282 = 6,785,764,282 Example 10: 1123 x 1003 numbers above the base 1123 + 123 Above the base we cross-add instead of subtracting 1003 + 3 1126 / 369 = 1,126,369 Example 11: 10004 103 10304 10004 x 103 multiplying numbers near different bases + 0004 Here the smaller number and its complement as far to + 03 the left as possible. The right side is obtained as usual, / 12 but since the smaller number only has 2 digits on the right so does the answer. On the left side the answer is Obtained by adding to the far left side. Example 12: 99998 96 95992 99998 x 96 different bases with numbers below the base - 00002 - 04 / 08 Example 13: 1004 x 98 different bases, above and below To share the same base 98 becomes 980, so it is in The position shown. 1004 + 004 Here the cross-wise operation is 98(0) + 4 = 984, or 98 - 02 1004 984 / -08 -02 983 / 92 984 Example 14: 9111 x 9900 9111 – 0889 9900 – 0100 9011 / 88900 9019 / 8900 When the numbers being multiplied are both below the base there will be as many digits on the right side as on the left. We add zeros to the deficiency to maintain the symmetry. Exercise 9 Try to find the answer mentally 1) 87 x 97 2) 78 x 98 3) 69 x 97 4) 98 x 86 5) 92 x 93 6) 73 x 98 7) 98 x 99 8) 88 x 96 9) 12 x 13 10) 13 x 11 11) 14 x 13 12) 112 x 112 Exercise 10 1) 103 x 92 2) 107 x 91 3) 1003 x 998 6) 103 x 104 7) 107 x 106 8) 1012 x 1011 11) 997 x 96 12) 9996 x 96 13) 977 x 97 4) 101 x 99 5) 14 x 9 9) 14 x 12 10) 1122 x 1007 14) 97 x 9 15) 9876 x 96 Answers Exercise 9 1. 8439 2. 7644 3. 6693 4. 8428 5. 8556 7. 9702 8. 8448 9. 156 10. 143 1. 9476 2. 9737 3. 1000994 7. 11342 8. 1023132 9. 168 13. 94769 14. 873 15. 948096 1. 572 2) 319 3) 3454 4) 4686 5) 57343 6) 80282 7) 23606 8)651387 9) 2390916 10) 3934579 1. 672 2) 504 3) 936 4) 1488 5) 7668 6) 25608 7) 61944 8) 854556 9) 350016 10) 32522580 1) 4554 2) 7326 3) 6435 4) 693306 5) 373626 6) 617382 7) 68413158 8) 9824501754 10) 92907 11) 749924 11. 182 6. 7154 12. 12544 Exercise 10 4. 9999 5. 126 10. 1129854 11. 95712 6. 10712 12. 959616 Exercise 11 Exercise 12 Exercise 13 15) 256397436 9) 654971345028 12) 5429457 13) 32399676 16) 36539346 17) 288999711 19) 432 20) 603 21) 1098 24) 5112 25) 12517447 18) 2684499973155 22) 35541 26) 59671269 14) 87199128 23) 455301 27) 25973001 28) 2561031 Exercise 14 1) 624 2) 2352 3) 3024 4) 2484 5) 158004 6) 479526 7) 280896 8) 252384 9) 109722 10) 613800 Vedic Math Multiplication by Specific Numbers Multiplication by 11 using the sutra “Antyayoreva” – “Only the last two digits” By using this sutra we do addition instead of multiplication, adding only the last two digits. Example 15: 4523 x 11 0 4523 0 Step 1: We place a zero at both ends of the number 0 4523 0 Step 2: Just continue to add the last 2 digits 3 045230 Step 3: Just continue to add the last 2 digits 5 3 045230 Step 4: Just continue to add the last 2 digits 7 5 3 045230 Continuing to add the last 2 digits we get the answer: 49753 497 5 3 Example 16: 35612 x 11 0356120 3911732 (6+5=11, so write 1, carry 1) Exercise 11: Multiply the following numbers by 11 1) 52 x 11 2) 29 x 11 3) 314 x 11 4) 426 x 11 6) 7462 x 11 7) 2146 x 11 8) 59217x11 9) 217356x11 5) 213 x 11 10) 357689 x 11 Vedic Math Multiplication by Specific Numbers Multiplication by 12 using the sutra: Sopantyadvayamantyam” – “The ultimate and twice the penultimate”. This sutra also uses addition instead of multiplication. As in the previous example we make a zero sandwich. Then we add the last digit and twice the penultimate (second last) digit. Example 18: 4523 x 12 0 4523 0 Step 1: We place a zero at both ends of the number 0 4523 0 Step 2: add the last digit plus twice the second to last 6 045230 Step 3: add the last digit plus twice the second to last 7 6 045230 1 Continue to add the last digit plus twice the second to last 2 7 6 045230 Continuing in the same way we get the answer: 54276 5 14 12 7 6 Example 19: 713624 x 12 = 8563488 Example 20: 3176214 x 12 = 38114568 07136240 031762140 8156131488 38112114568 Exercise 12: multiply the following numbers by 12 1) 56 x 12 6) 2134 x 12 2) 42 x 12 3) 78 x 12 7) 5162 x 12 4) 124 x 12 8) 71213 x 12 5) 639 x 12 9) 21968 x 12 Vedic Math Multiplication by Specific Numbers Multiplication by 9 using the sutras “Ekanyunena Purvena” – “By one less than the one before” “Nikhilam Navatascaramam Dasatah” – “All from 9 and last from 10” First type: when all the digits of the multiplier and multiplicand are the same and all the digits of the multiplier are 9’s. Example 20: 342 x 999 = 341658 Step 1: We divide our answer in 2 parts, the left side (LS) and the right side (RS). LS: 341 / Step 2: We write 1 less than the multiplicand: 342-1=341 RS: 341 / 658 Step 3: We write the complement of the multiplicand using “all from 9 and last from 10”. Compliment of 342=658 OR, subtract each digit of the LS of the answer from 9: (9-3=6), (9-4=5), (9-1=8) = 658 Example 21: 5642 x 9999 = 5641 / 4358 = 54614358 Example 22: 71496 x 99999 = 71495 / 28504 = 7149528504 Second Type: the digits in the multiplier are more than the multiplicand. This is as easy as the previous example. We simply have to add zeros before the multiplicand and make the number of digits equal to the digits of the multiplier. Example 23: 23 x 999 = 22977 Step 1: Since the multiplicand has 2 digits and the multiplier 3 digits we make 023 x 999 the multiplicand 023 so that they both have the same number of digits. 22 / Step 2: LS: we write one less than the multiplicand 22 / 977 Step 3: RS is the complement of 023 = 977 Example 24: 548 x 99999 = 00548 x 99999 00547 / 99452 = 54799452 Example 25: 7825 x 9999999=0007825 x 99999 7824/9992175 = 78249992175 Third Type: Here the number of digits in the multiplier are LESS than the digits in the multiplicand, and the multiplier is all 9’s. Example 26: 436 x 99 = 43164 Step 1: We divide our multiplicand into 2 parts so that the RS has the same number of digits as the number of 9’s in the multiplier. There are two 9’s in the multiplier so there are two digits on RS 4 : 36 separated by a colon. 4: 36 - 5 LS: we add 1 to the left part; 4 + 1 = 5, and subtract it from the RS: 436 – 5 4 : 31 431 / 64 RS: write the complement of the right part next to the left part. (complement of 36 = 64). Example 27: 20462 x 999 = 20441538 20 : 462 LS: add 1 to the left part and subtract it 20 : 462 - 21 20441 / 20441 / 538 RS: is the complement of 462 Exercise 13: Solve the following. (See if you can find the answer mentally): 1) 46 x 99 2) 74 x 99 7) 6842x99 8) 98246x99999 12) 543 x 9999 3) 65 x 99 9) 654972 x 999999 10) 93 x 999 11) 76 x 9999 13) 324 x 99999 16) 3654 x 99999 17) 289 x 999999 20) 67 x 9 21) 122 x 9 25) 1253 x 999 4) 694 x 999 5) 374 x 99 6) 618 x 99 14) 872 x 99999 18) 26845 x 99999999 22) 359 x 99 26) 59731 x 999 15) 2564 x 99999 19) 48 x 9 23) 4599 x 99 24) 568 x 9 27) 25999 x 999 28) 25869 x 99 Vedic Math Working Base Multiplication We have demonstrated multiplication of numbers close to any one base, but when both numbers are not close to a convenient power of 10 we use what we call a “working base” which is a multiple or sub-multiple of 10, 100, 1000, etc. We then do our multiplication as we have already learned taking the working base into account. When using working bases we apply the sutra: “Anurupyena” – “Proportionality” For example, is we want to multiply 46 x 53, both numbers are far from 10 or 100, but close to 50, so we use 50 as our working base. This can be done in two ways: 10 x 5 = 50; here 10 is the theoretical base, and 50 is the working base, or 100/2 = 50; here 100 is the theoretical base, and 50 is the working base The theoretical base is important when we have to decide the number of digits on the right side of the answer. With a theoretical base of 10 there is only one digit on the RS; with a theoretical base of 100 there will be two digits on the RS. Example 28: 52 x 54 = 2808 Step 1: We will use 10 as the theoretical base and 10 x 5 = 50 as the working base. 10 x 5 = 50 Step 2: we place the complements of the working base next 54 +4 to them. 54 is more than base 50 and a + indicates this 52 +2 52 is greater than base 50, indicated by +2 56 / 8 Step 3: multiply the RS and add crosswise to find the LS Step 4: Now we proportionately multiply the LS answer to get The theoretical base from the working base 56 x 5 = 280 280 LS and 8 RS = 2808 Example 29: 523 X 488 = 255224 Step 1: we will use 100 as the theoretical base and 500 as the working base 100 x 5 = 500 Step 2: find the complements 523 + 23 Step 3: multiply the complements to get (MINUS) -276 488 - 12 Step 4: cross-subtract 511 / -276 Step 5: multiply the LS x 5 to return to theoretical base Working Base Multiplication, continued 511 x 5 = 2555 – 2 = 2553 now carry MINUS 2 to the LS Since we have -76 on the RS. To make it positive we 2553 – 1 / 24 take the complement of 76 = 24. and subtract 1 extra = 255224 on the LS for coming out of complements. Example 30: 62 x 68 = 4216 By two different working bases 10 x 6 = 60 62 + 2 68 + 8 70 / 16 421 / 6 We take 10 as the theoretical base, and 60 as the working base. Next we take the complements from the working base and get the answer in 2 parts. For the RS we multiply, and since the theoretical base is 10 we need one digit, so write 6 and carry 1. The LS is obtained by cross-addition, and multiply the result by 6: 70 x 6 = 420 plus 1 carry = 421. Answer: 4216 Next we will use the working base of 70. 10 x 7 = 70 62 - 8 68 - 2 60 / 16 The complements are now negative. We get our answer in 2 parts, as normal. Now multiply the LS x 7: 60 x 7 = 420 + 1 carry = 421 Answer: 4216 Example 31: 523 x 488 = 255224 We will take 100 as the theoretical base and 500 as the working base 100 x 5=500 523 + 23 488 - 12 511 / -276 2552 / 24 Since 100 is the theoretical base we need 2 digits on the RS. Therefore we write 76 and carry over MINUS 2 to the LS. First we multiply 511 x 5=2555, now -2 = 2553. On the RS we have a negative number so we must use its complement = 24, and subtract 1 extra for coming out of complements. Answer: 255224 Exercise 14 1) 24 x 26 6) 687 x 698 2) 49 x 48 3) 56 x 54 4) 54 x 46 5) 399 x 396 7) 532 x 528 8) 478 x 528 9) 478 x 399 10)775 x 792 Vedic Math The Vinculum Calculations can be considerably simplified by the use of the “vinculum”. This is the name of a minus when it is put on top of a number. For example, -1 written in its vinculum form is 1, also described as “bar 1”. We can use the vinculum to make big numbers small. For example, 29 can be written as 31, meaning 30 -1. If we use 31 instead of 29 we avoid having to deal with 9. The vinculum is an ingenious method that has many advantages, among which are: 1. it gives flexibility – we use the vinculum when we want to 2. larger numbers – 6, 7, 8, 9 can be avoided 3. numbers can cancel each other out or made to cancel 4. 0 and 1 occur twice as frequently as they otherwise would We will find the sutra: “all from 9 and last from 10” useful in putting a number into vinculum from, or taking it out of vinculum from. Example 32: find the vinculum of 29878 The vinculum is found by increasing the first number to 3 and applying the sutra to the remaining numbers: The vinculum of 29878 = 30122 Example 33: use the vinculum to eliminate the big numbers in 387179 For this number we split it into two parts: 387 / 179 and apply the sutra to each part: 387179 = 413221 Further examples of putting a number in vinculum form are: 293 = 313, 83 = 123, 800 = 1200, 185 = 225 or 215, 909 = 1 1 1 1 817 = 8 2 3 or 1 1 8 3 or 1 2 2 3 Example 34: taking a number out of vinculum form 42132 = 37868 the 4 is decreased to 3 and the sutra applied to the rest. Example 35: further examples of removal of the vinculum: 4 1 1 3 2 2 1 = 3892781, 703 = 697, 7 2 0 3 = 6797, 27 = -13 Simple applications of the Vinculum Example 36: 29 x 3 we can avoid working with a large number by using the vinculum, writing the vinculum from: 31 x 3 = 3 x 93 = 87 Example 37: 261 ÷ 9 9 ) 2 6 11 3 1 = 29