Math tricks for number theory
10
Math Tricks for Number Theory Finda Dwi Permatahati (110210101011) Dini Mustika Sari (110210101013) Fajri Maulana (110210101014)
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It is about The uniqueness of number 9.
Transcript of Math tricks for number theory
Math Tricks for Number Theory
Finda Dwi Permatahati (110210101011)
Dini Mustika Sari (110210101013)
Fajri Maulana (110210101014)
Multiplication by 25
24 x 25 =
?: 4 = 6 x 100 = 600
Multiplication by 25
24 x 25 =
: 4 = 6 x 100
24 x 25 =
2425
x 120
+600
= 60048
?
Multiplication by 25
123 x 25 =
? : 4 = 30 x 100
= 3000Remain = 3 x 25
Result =3075= 75
Exercises
4545 x 25 = ?278 x 25 =
?
12
The Uniqueness of Number
92468a7a =
?Can be divided by 9
The Uniqueness of Number
2468a7
2+4+6+8+a+7= 9k
Integer number a+27=
9k a = 0 or a = 9
9
Proof
246807 : 9 = 27423246897 : 9 = 27433
There’s no remain
Exercise
4545450009321
4895p2
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