Fun And Interactive Missing Number Worksheets For Little Ones Missing number worksheets are a great activity for preschoolers and kindergarteners. It helps to reinforce their counting skills. It also teaches them the skill of 'filling in the blanks,' and learning to count from random numbers. Learning numbers is essential. It lays the foundation for further math learning. To successfully complete these worksheets, your preschooler / kindergartner needs to be able to know the numbers in order, and be able to write the numbers. Our missing number worksheets make learning math fun and interactive. There are a variety of cartoon characters