37 printable or digital pages to help your students improve their critical thinking skills regarding numbers. Each page offers five CLUES to discovering a secret number. Clues tell the student if the number is... if it is odd or even, whether it is single or double digit, if it is a prime or composite number, if it is a square number (4, 9, 16, 25…), if it is a triangular number (the sum of 1+2+3+4…), if it is a cube number (e.g., 8 = 2x2x2, 27 = 3x3x3), how many syllables it has, if it has an