The Grids for Kids Complete and the Crack the Code Complete collections from The Math Profs are a great way to incorporate logic and critical thinking skills into the school day. The series contains over 330 puzzles with various levels of difficulty. 

I often include critical thinking activities in my children's education. It is essential that they exercise their brains to learn to think for themselves and solve problems. In addition, we believe in the value of identifying and evaluating evidence to guide that decision-making. My favorite way to encourage this type of learning is through grid puzzles. 

My children love grid puzzles! If there is one in a puzzle book, there is always a race to see who will find and complete it first. Their ages range from 7 to 16, so it is often tricky to find puzzles to match each of their levels. I love the Grids for Kids Complete series because there are plenty of options for all the children. There are five levels of puzzles with an additional supplemental book for levels 1-3, making a total of eight downloads in the complete collection. Each book contains five types of grid puzzles, with six of each type. Each puzzle in a style uses the same logical structure for its clues. The story, categories, and objects vary, and the clues' order changes, but the logic is the same. In this way, a child can learn a type and then have the chance to master it before moving on to more complicated types of puzzles. 

All grid puzzles follow the same format. First, a list of clues follows a short story or explanation. Then, the reader uses that information to fill in the grid. For instance, while deciphering the ages and favorite fruits of four brothers in Puzzle 1F in the Level 4 book, one clue says, "Ethan is seven years old and likes apples." Therefore, the reader would put a check by Ethan's name for those things and an X for the other options. Then, he would put an X by the other boys' names for seven and apples. Some of the information is plainly given, some is gleaned through elimination, and some is deduced through logic.

The books contain tutorials that walk through the first grid of each type of puzzle step-by-step through the solution process. The tutorials are clear and detailed. The answers to all thirty puzzles are also included in the back of the book.   

While my children were already familiar with the grid puzzles, the Crack the Safe Complete books were a new challenge. These puzzles are like the old Mastermind game where one person creates a code using colored pegs, and another person tries to crack the code using a combination of trial and error, the process of elimination, and logic.  

The goal in these books is for the student to crack the safe by solving the combination locks using a sequence of digits from 1-9. There are three levels in this series, with each book transitioning from easier to more difficult within each one. Level 1 has three unique digits for each lock, Level 2 also has three digits but allows repetition of numbers, and Level 3 requires four unique digits. 

The clues for each lock are given as guesses for the combination. The guesses are checked with the Accuracy Indicator, meaning if a correct number is used and is in the correct position, a red bulb lights up; if a correct number is used but is in an incorrect position, a white bulb lights up. The clues are already completely formed, resulting in a process that depends on pure reasoning for solving.   

There is a warm-up example at the beginning of each book that takes the student through the process of solving the combination. All answers are also in the back of the book with detailed explanation steps. 

As I expected, they gravitated toward the grid puzzles. Having varying difficulty levels is perfect for our family since there are puzzles for the first grader, the eleventh grader, and everyone in between. Even though the lock puzzles were new for them, my children enjoyed them, as well. I was pleased to see how they progressed over time as they became more familiar with this puzzle style.      

The Grids for Kids Complete and the Crack the Code Complete collections build logical thinking in a fun way and would be a beneficial addition to any classroom.

-Product review by Erika Leaf, The Old Schoolhouse® March 2022