Fluency and flexibility with numbers are the hallmarks of mathematical thinking. For our students to excel in mathematics, they must understand how numbers can be composed and decomposed. That’s why learning the combinations for numbers to 10 should be the primary focus in our Kindergarten and 1st-grade classrooms. Not convinced? Check out where a number bond goes after Kindergarten.
Like all instruction, to be effective, composing and decomposing activities, which can also be thought of as part/whole activities, should be differentiated. That is, students should be working on the combinations of a number at their level. It does no good for a student to practice combinations for 8 if they don’t know the combinations for 5. Check out this blog post for more information on differentiating and grab an easy recording sheet.
An activity called the hiding assessment is a useful assessment for determining a child’s number. In this short video, a 2nd-grade teacher is using missing part flashcards to assess a student’s proficiency with the combinations for 4. It looks like the student is quite proficient with 4, so the teacher would next test the student on combinations for 5. When a student can’t fluently provide the missing part, that becomes the student’s number. For example, if a student can’t supply 3 as the missing part for 5 when 2 is shown, 5 is the student’s number, and he will have activities to practice combinations for 5.