Moving along a number line is an essential skill for basic counting, adding one more, one less, addition and subtraction as well as to demonstrate counting in 2s, 5s etc.
Having signs on the playground that support this teaching allows for children to physically experience putting their finger or chalk mark on a number and move forwards or backwards in number jumps that are much easier to see and feel than small, desk-based number lines..
This wide range of number lines can support many abilities in their maths learning.