What sequence of the following instructions should be followed in development of a mathematical concept in elementary classes?
I. Drawing pictures
II. Using symbolic representation
III. Providing experiences
IV. Explaining through language

The correct option is III, IV, I, II.

According to educational psychology and teaching methodologies (such as Bruner's stages of representation and the ELPS sequence for learning mathematical concepts), children learn abstract mathematical concepts best when guided through a specific hierarchical sequence:

1. Providing experiences (III): Learning starts with concrete, hands-on experiences using real objects or physical manipulatives so that children can visually and physically interact with the concept.

2. Explaining through language (IV): Following concrete experiences, children use spoken language to describe, discuss, and explain what they experienced, helping to clarify and solidify their initial understanding.

3. Drawing pictures (I): Next, the concept is represented visually or pictorially (iconic stage). Children transition from physical objects to diagrams, drawings, or images that represent the concept.

4. Using symbolic representation (II): Finally, abstract symbols, numerals, and mathematical notation (symbolic stage) are introduced to represent the concept formally.

Therefore, the correct chronological sequence for developing a mathematical concept in elementary classes is III, IV, I, II.