Simple Cross Number is constructed on a crossword grid just like a standard crossword, but the digits 1 to 9 are used instead of the letters of the alphabet. In a Cross Number Puzzle, the Across and Down clues are sums, subtraction, multiplication, or division of the digits in the across and down words. The rules are simple: 1.The empty cells should contain numbers from 1 through 9 2.The clues in the rightmost cell and the lowest cell tells the sums, subtraction, multiplication, or division of the numbers before that clue. (on the right or down) 3.The numbers in empty cells must be unique. No number should be used more than once. 4. Use regular math order of operations ( x ÷ precedes + - ) Book features: This book contains 180 Cross Number Puzzles Large-print Book. very easy to read, and fill out. Large and Easy To Read Font 2 puzzles per page, solving could be easy on your eyes An answer key for each puzzle Puzzles are printed on high-quality white paper, size 8,5 x 11 inches By using this selection of sudoku puzzle books you would experience enhanced brain capabilities for example focus, logical thinking, and memory. Perfect puzzle book collections as a special gift for your loved ones Choose your book today by clicking on the BUY NOW button at the top of this page. Get Your Book NOW!