Numberskull is a great new puzzle devised by David Wolstenholme of Topaccolades Limited.
A Numberskull puzzle
consists of a grid with 6 = signs and 6 whole number results already on
it, together with 9 given whole numbers, all different. The puzzler simply has to fill in the grid by placing each of
the nine numbers into the nine white squares, one in each, and placing
any one of the four basic arithmetic operators (+, -, x,
÷) into the grey squares, so that 6 correct equations are formed
(3 in left-to-right rows, 3 in top-to-bottom columns).
that the first operation is always evaluated first and its result is
used in the second operation to produce the overall result. So, 3 + 4 x 2 means (3 + 4) x 2, which simplifies to 7 x 2
and equals 14. It does not
mean 3 + (4 x 2) which simplifies to 3 + 8 and equals 11.
is a unique solution. This can be found a step at a time, with no
guessing required, by using arithmetic to determine some of the possible
ways of achieving the results with the given numbers and, where
necessary, by then applying logic to determine more about the positions
of the numbers.
also produce Numberskull puzzles in which some of the given numbers and
operators are already placed on the grid.
This can make the puzzle easier to solve.
To find out more about Numberskull, including
Numberskull is also integrated into the CompactNumbers and CompactPuzzles packages found at www.compactfun.com