Which of the following model is least appropriate to develop the conceptual understanding regarding the relationships of ones, tens and hundreds in early grade learners ?

Correct option is C

The place value chart is a symbolic representation of place value, and while it helps in organizing numbers, it does not offer a concrete or tactile experience.
In early grades, children need manipulatives and visual tools (like abacus or Dienes blocks) to physically experience regrouping and base-10 relationships.
From the options 
A. Money: Although imperfect due to non-decimal coins, it can still offer concrete, relatable experiences if simplified.
B. Abacus: Visually shows place value and regrouping in a tactile way — suitable for early learners.
C. Place Value Chart: Too abstract for early learners without prior hands-on experience — hence least appropriate.
D. Dienes Blocks: Ideal concrete tool for demonstrating base-10 structure and regrouping.
Conclusion:
While all tools have value, for early grade learners, we prioritize concrete and tactile experiences.
So, Option C – Place Value Chart is the least appropriate as an introductory model.