1. Number Theory
GROUP 3th
1.RIZKY TITIE R . (110210101029)
2.SHOFIA HIDAYAH (110210101036)
3.MARLIA SARI P . (110210101087)

2. Math TrickMath Trick Black HoleBlack Hole
Number TheoryNumber Theory

3. Math TrickMath TrickMultiply byMultiply by
11s11s
55s55s
77s77s
99s99s
88s88s

4. 362537892 x 11 = …
39878(10)(15)(17)(11)2
3987916812
So, 362537892 x 11 = 3987916812
Math TrickMath TrickMultiply byMultiply by
11s11s
55s55s
77s77s
99s99s
88s88s

5. 625178342 x 55 = …
30(40)(35)(30)(40)(75)(55)
(35)(30)10
34384808810
So, 625178342 x 55 = 34384808810
Math TrickMath TrickMultiply byMultiply by
11s11s
55s55s
77s77s
99s99s
88s88s

6. 934358621 x 77 = …
63(84)(49)(49)(56)(91)(98)
(56)(21)7
71945613817
So, 934358621 x 77 = 71945613817
Math TrickMath TrickMultiply byMultiply by
11s11s
55s55s
77s77s
99s99s
88s88s

7. 7464153246 x 88 = …
56(88)(80)(80)(40)(48)(64)
(40)(48)(80)(48)
656845485648
So, 7464153246 x 88 = 656845485648
Math TrickMath TrickMultiply byMultiply by
11s11s
55s55s
77s77s
99s99s
88s88s

8. 62534253722 x 99 = …
54(72)(63)(72)(63)(54)(63)
(72)(90)(81)(36)(18)
6190891118478
So, 62534253722 x 99 = 6190891118478
Math TrickMath TrickMultiply byMultiply by
11s11s
55s55s
77s77s
99s99s
88s88s

9. Black HoleBlack Hole
)(3)(4
343434
)34()34()34(
cbacba
ccbbaa
ccbbaa
cba
−+=−+
−=−+−
−=−+−
=+
34 =
34 =
Prove :

10. Black HoleBlack Hole
0.30.4
)(3)(4
)2.().........(3)(4
343434
)34()34()34(
)1......(..........
=
−=−
−+=−+
−=−+−
−=−+−
=+
cccc
cbacba
ccbbaa
ccbbaa
cba
34 ≠
Prove :
we can’t cancel 0 on the right and the left side because
if we cancel it, it means we divide 0 by 0 and the result
is undefined.

11.  THANK YOU 