Solution

26211

Problem
Three neighbours Back to problem
First name
Louis Garland
School
Solihull School
Country
England
Age
12

Adding three consecutive number results in 3 multiplied by the middle number. For example 1+2+3=6, and 3x2=6. Or 2+3+4=9 and 3x3=9. With this pattern we can work out 96+97+98 by working out 3x97=291. Or even colossal numbers like 1209865+1209866+1209867 by doing 3x1209866=3629598.

Put simply adding three consecutive number is the second number times three.