Four Big Puzzles on One Sheet
A 4x4 square takes longer than a 3x3 one, so four of them fill a lesson or a long evening. The grids are drawn large enough for every number to be written clearly, and each square on the page has blanks of its own.
A Step Up From 3x3
With sixteen cells, a missing number can often be reached from more than one line, and the best first move is the line with a single blank. Solvers learn to scan the rows, then the columns, then the diagonals, and to come back to a line once a crossing cell is filled.
When the Total Is Not Printed
On most pages the totals are left out. Find a line with all four of its numbers in place and add them: that is what every line of that square must reach. Built from 1 to 16, a square always totals 34; with larger numbers, each square needs its own addition.