Once upon a time, in a land full of numbers, there was a detective named Detective Math. He was very good at solving math problems and loved to help people with their calculations. One day, he received a mysterious letter from the Math Kingdom. The letter said that a number had gone missing from all the math problems in the kingdom. Detective Math knew he had to solve this mystery!

Detective Math packed his magnifying glass, notebook, and pencil, and set off on his exciting quest. He arrived at the Math Kingdom, a place filled with colorful numbers and friendly math symbols. The kingdom was worried because without that missing number, their calculations were all wrong!

Detective Math started investigating by talking to the numbers and symbols. He asked them if they had seen anything strange or unusual. The numbers and symbols were scared and confused. They didn't know where the missing number had gone!

As Detective Math continued his investigation, he came across a tricky math problem. It said, '5 + ? = 10'. Detective Math knew that the missing number was the one that made the equation correct. He thought hard and realized that the missing number was 5! He quickly solved the problem and felt closer to solving the mystery.

After solving many more math problems and puzzles, Detective Math finally discovered a mischievous number thief hiding in a secret cave. The thief was a little number named Zero. Zero had taken the missing number because he wanted to be the only number in the Math Kingdom. Detective Math explained to Zero that all numbers were important and that they needed to work together.