Simple math tricks and hints. :)

1. 20August 2013
MATH
MAGIC
20 August 2013

2. MULTIPLICATION
TRICKS

3. CROSS-
MULPLICATION
14
X 12

4. First, to get the last digit in the answer,
multiply the two numbers on the right.
Write the answer, as the rightmost digit in
the problem’s answer.

5. 2x4=8
14
X 12
8

6. Now, get the middle digit, cross-
multiply both sets of numbers, and
then add the together.

7. 1 x 2 = 2
1 x 4 = 4
6
14
X 12
68

8. Lastly to get the last digit, simply
multiply the left digits.

9. 1 x 1= 1
14
X 12
168

10. TRY!
28
X 23
In this case, we will do the carrying procedure.

11. COMPLEMENTARY
MULTIPLICATION
96
x 94

12. First, subtract both numbers in 100
and list the difference.
100 - 96 = 4
100 - 94 = 6

13. Second step is to subtract diagonally.
You will notice there that they will give
the same answer, and this will be your
base number.

14. 96 – 6 = 90
94 – 4 = 90

15. 96
x 94
90

16. Third, multiply the two numbers we
got by figuring the difference
between the original numbers and
100.
4 x 6 = 24

17. •Lastly, write it to the right of the
base number.
96
x 94
9,024

18. •If the number are larger than 100, add
the difference instead of subtracting.
Ex.
103
x 107

19. 103 – 100 = 3
107 – 100 = 7
103 + 7 = 110
107 + 3 = 110

20. •You will arrive with same answer
then write it as the base number.
103
x 107
110

21. •Multiply the 3 and 7, then write it as
the base number.
3 x 7 = 21

22. 103
x 107
11,021

23. This method is applicable also in numbers around
50.
Ex.
46
x 44

24. MULTIPLYING BY 11
18
X 11

25. •Add the two digits and insert the
sum between the digits.
1 + 8 = 9

26. 18
X 11
198

27. 99
X 11
In case that you got a two-digit number, add
that numbers’ left digit to the digit in the
original number.

28. 9 + 9 = 18
99
X 11
1,089

29. SQUARING TRICKS

30. Squaring a number around 100
If the number falls under 100 and above
50, you simply figure the difference
between 100 and the number.
96²

31. •Subtract the difference from the
number being squared, and write the
answer as the first digits in your
answer.
100 – 96 = 4

32. 96²
- 4
92 base number 92(00)

33. •Take the difference between 100
and the number being squared and
square.
100 – 96 = 4
4² = 16

34. •Place that number after the base
number and you have the answer.
96² = 9,216

35. If the number to be squared is
more than 100, add the
difference to the number.

36. Squaring numbers that ends in
5
Any number that ends in 5 is easy to
square to start with, you know that
5 x 5 = 25, so the answer will
automatically end in 25.
Ex. 35²

37. •Add 1 to the first digit, ignore the
rest at the number.
1
+ 3(5)
4

38. •Multiply the result to the first digit
of the original number. This result is
the first part of the answer.
4 x 3 = 12

39. 12 with 25 makes 1, 225.
Try!
85²
115²
65²

40. SHORTCUT AND HELPFUL HINTS
18 X 101 = 1,818
84 X 101 = 8,484
97 X 101 = 9,797
102 X 101 = 10,302
621 X 101 = 62,721

41. Thank you!