Lesson 4

MULTIPLICATION BY 12:

The method is exactly the same as in the case of 11 except that you double each number before adding the right neighbor.

digit i.e till 0

1234 x12= 01234x12 =

Here 2 multiply by 4 write 8 at extreme right . ...... 8

Double 3 and add to 4 and write before ...8

6+4=10 here we write 0 before 8 and take 1 carry .....08

Double 2 and add to 3 and add carry1 and write before 08 ,4 +3 +1 =8 .....808

Double 1 and add to 2 and write before ...808, 2+ 2 =4 ....4808

Double 0 and add to 1 and write before .4808 0+1=1 14808

MULTIPLICATION FROM 13 TO 19:

The method is exactly the same as in the case of 12 except that you treble each degit before add in the

right neighbor, in the case of multiplication of 13 .We would quadruple (i.e. multiply by 4) and then add the right neighbor, in the case of multiplication of 14 .In case of 19 we would multiply by 9 and then add the right neighbor.

39942 X 13 = ?

039942x13=

2x3 =6 ........................ 6

4x3+2 =14 .................46

9x3+4+1 =32 ...........246

9x3+9+3=39 ..........9246

3x3+9+3=21 ........19246

0x3+3+2=5........ 519246

34x17 =? 034x17

4x7 =28 ...............8

3x7+4+2 =27 .....78

0x7 +3+2=5..... 578

1) 39942 X 13 = ? 039942 X 13 519246

2) 43285 X 14 = ? 043285 X 14 605990

3) 58265 X 15 = ? 058265 X 15 873975

4) 36987 X 16 = ? 036987 X 16 591792

5) 69873 X 17 = ? 069873 X 17 1187841

6) 96325 X 18 = ? 096325 X 18 1733850

7) 74125 X 19 = ? 074125 X 19

24678 x 13= 246x13x 15= 89x19 x18=

98745 x14= 987 x19 = 266x16=

98745 x17= 8745x 12 = 3435 x12=

Check your answer with the help of calculator

**MULTIPLICATION OF 12 TO 19**MULTIPLICATION BY 12:

The method is exactly the same as in the case of 11 except that you double each number before adding the right neighbor.

**Step1**Prefix 0 before multiplicand**Step2**Multiply last digit by 2 and write it at extreme right take carry if there is**Step3**Double and add the right neighbor with carry in step first repeat this up to the firstdigit i.e till 0

1234 x12= 01234x12 =

Here 2 multiply by 4 write 8 at extreme right . ...... 8

Double 3 and add to 4 and write before ...8

6+4=10 here we write 0 before 8 and take 1 carry .....08

Double 2 and add to 3 and add carry1 and write before 08 ,4 +3 +1 =8 .....808

Double 1 and add to 2 and write before ...808, 2+ 2 =4 ....4808

Double 0 and add to 1 and write before .4808 0+1=1 14808

**14808 is our required answer**MULTIPLICATION FROM 13 TO 19:

The method is exactly the same as in the case of 12 except that you treble each degit before add in the

right neighbor, in the case of multiplication of 13 .We would quadruple (i.e. multiply by 4) and then add the right neighbor, in the case of multiplication of 14 .In case of 19 we would multiply by 9 and then add the right neighbor.

39942 X 13 = ?

039942x13=

2x3 =6 ........................ 6

4x3+2 =14 .................46

9x3+4+1 =32 ...........246

9x3+9+3=39 ..........9246

3x3+9+3=21 ........19246

0x3+3+2=5........ 519246

**519246 is our required answer.**34x17 =? 034x17

4x7 =28 ...............8

3x7+4+2 =27 .....78

0x7 +3+2=5..... 578

**578 is our required answer.****Now try these examples**1) 39942 X 13 = ? 039942 X 13 519246

2) 43285 X 14 = ? 043285 X 14 605990

3) 58265 X 15 = ? 058265 X 15 873975

4) 36987 X 16 = ? 036987 X 16 591792

5) 69873 X 17 = ? 069873 X 17 1187841

6) 96325 X 18 = ? 096325 X 18 1733850

7) 74125 X 19 = ? 074125 X 19

**Practice Test**24678 x 13= 246x13x 15= 89x19 x18=

98745 x14= 987 x19 = 266x16=

98745 x17= 8745x 12 = 3435 x12=

Check your answer with the help of calculator