Since the range of numbers is determined by the block to which it is attached.

You do not need to worry if the Random Input block will input an invalid value to a block. Okay, this is the same policy as advocated by Megos answer, but let me make another case for it. Using random value makes the program have change each time. Random Input block can be used as input for many blocks, such as Wait For block, Play Sound block and Motor Power block etc. In this post, let me introduce some tips to make LEGO WeDo 2.0 stretch to its full length. However, if you are seriously enough to use WeDo 2.0, you could find some ways to work around WeDo 2.0 programming constraints and inject some flexibility to LEGO WeDo 2.0 models. Since generally WeDo 2.0 focuses on mechanical structure of the model and scientific and engineering concept learning, the programming function is an auxiliary one, helping kids to experience simple programming. There are not so many functionality blocks to choose from, and lack of many basic functions such as conditional judgement, variable creation, or control structures, etc. LEGO WeDo 2.0 Programming Blocks have friendly interface, but if you want to program some fun things inside, you might get frustrated.

Lego wedo program