A number line uses a model of length. Each number is represented by its length from zero. Number lines can be confusing for young children. Students have to count the "hops" they take between numbers instead of counting the numbers themselves. Students' fingers can land in the spaces between numbers on a number line, leaving kids unsure which number to choose.
I have been using number paths for a few years and highly recommend them for use in Kindergarten and First grade.
Most major publishers are not yet utilizing number paths. So, I wrote some word problems using number paths. CLICK HERE to download the free samples shown below.
The first level, Addition and Subtraction within Ten, is free. CLICK HERE to grab the free version.
The full school version with all levels is available here:
https://apps.apple.com/app/id698772777
We are offering this full version through the Volume Purchase Plan as well here:
https://volume.itunes.apple.com/us/app/math-word-problems-addition/id698772777