Problem Solver +/- (Adding/Subtracting)

Solves all types of problems, with flexible strategies and known combinations. Multidigits may be solved by incrementing tens and ones by counting.



You may see this:

Linked Image to Sign In/Sign Up page

Other Examples:

  • Asked, "What's 28 + 35?", incrementer thinks: "20 ... 30, 40, 50; then 58, 59, 60, 61, 62, 63."
  • Asked, "If I have 13 and you have 9, how could we have the same number?", says, "9 and 1 is 10, then 3 more to make 13. 1 and 3 is 4. I need 4 more!"
  • Combining tens and one: "20 + 30 = 50.”
  • A child thinks “8 + 5 is like 8 plus 2 and 3 more, so, it's 13.”

Help your student become a(n) Problem Solver +/- (Adding/Subtracting)

These activities challenge children to solve all the addition and including some multidigit problems.  Children continue to build and use sophisticated  strategies, and can discuss the relationship between problems and operations. For example, for a Separate, start unknown, problem such as "You had some candies, and you gave your friend  8 , now you have 5. How many did you have to start with?" a child might say, "It is like a subtraction problem, but you don't know the whole, so you got to add 8 and 5."  If children need more help using early counting strategies using tens and ones, use the Counting activity "Moving on Grids
[Counter Forward and Back (10s and 1s)]."

Special Thanks To

Institute of Education Sciences
The research reported here was supported by the Institute of Education Sciences, U.S. Department of Education, through grant numbers R305K050157, R305A120813, R305A110188, and R305A150243. to the University of Denver. The opinions expressed are those of the authors and do not represent views of the Institute or the U.S. Department of Education.