0

39 x 94 = (39)·(94) = (30 + 9)·(90 + 4)
= 27x100 + 12x10 + (   )x10 + 36
= 2700 + 120 + (   )x10 + 36 =     3666

0

81

82

83

84

85

86

87

88

89

90

  1 of 30

FirstOuterInnerLast

 

Level

1

2

3

4

How Many

5

10

20

30

50

  

FOIL method @

 

Example >>>

 34 x 52 =  (30 + 4)·(50 + 2)

 

 

 

  

First

(A + B)·(C + D) = AC + AD + BC + BD

= 30 x 50

= 1500

Outer

(A + B)·(C + D) = AC + AD + BC + BD

= 30 x 2

=     60

Inner

(A + B)·(C + D) = AC + AD + BC + BD

= 4 x 50

=   200

Last

(A + B)·(C + D) = AC + AD + BC + BD

= 4 x 2

=       8

 

 

    

 

  

 

= 1768