Which of the following is a desirable practice in the context of teaching and…

Concept: Constructivist pedagogy holds that mathematical understanding is built when learners actively construct meaning through hands-on exploration and self-devised strategies, rather than receiving a ready-made rule to apply. The teacher's role is to pose a concrete situation and let learners grapple with it, formalising the procedure only after understanding has emerged from that experience.

Application: For teaching measurement of volume, this principle translates into giving learners real objects and containers and encouraging them to invent and test their own ways of finding volume — for instance, packing a box with unit cubes or using displacement — before any formula is introduced. This experience-first approach makes the eventual formula meaningful rather than an arbitrary rule to memorise.

Cross-check: Contrasting the other suggested practices confirms this:

• Handing over the cube-volume formula at the very start skips the exploration stage and turns the lesson into rote application of a memorised rule.

• Insisting on numerically precise answers from the outset shifts the focus to computation before learners have built any conceptual sense of what volume represents.

• Starting with the measure of 2-D figures is a category error, since flat figures have area, not volume, so it does not build toward the three-dimensional concept at all.

Because it lets learners discover and justify their own method for finding volume through direct experience with objects, encouraging students to figure out ways to calculate the volume of different objects is the pedagogically desirable practice here.