Maryland Grade 2 Science

Rebuild an object with the same pieces

Compare two structures made from the same blocks, use observations to explain the change, and read Maryland Grade 2 science references.

The Maryland science directory (archived state copy) links the Next Generation Science Standards publisher. The state standards catalog identifies the 2013 NGSS framework. The Publisher’s September 2017 DCI arrangement of the 2013 Next Generation Science Standards supplies the selected expectation and its practices, core ideas, crosscutting concepts, clarifications, and boundaries. Its September 2017 arrangement date is not a new Maryland adoption. The live MSDE site displayed a maintenance notice during review and linked an archived backup; working archived state references are labeled here. Check the school’s course plan and MSDE updates for later changes. This activity selects a Grade 2 expectation. It is one part of a science course, not a complete curriculum.

One set of blocks, two different structures

A class builds a short bridge from eight identical connecting blocks. The teacher photographs it, takes it apart, and rebuilds those same eight blocks as a tower. No pieces are added or discarded. Students count the pieces and compare the two arrangements. What changed, and what stayed the same? The record below describes an invented classroom example. In an actual activity, students should record their own observations and use materials selected for their classroom.

Explain the evidence or model

The bridge and tower have different arrangements, but both contain the same eight pieces. Taking the bridge apart separates its components without changing each block into a different material. Reconnecting them changes where the pieces sit relative to one another and can change the structure’s overall shape and use. An evidence-based account names the starting object, describes the separation, and explains the new arrangement. Saying it became taller is useful only if that was observed; saying the blocks turned into new matter would not describe this process. A photograph or labeled drawing helps another student follow the sequence.

What to check in the explanation

A count of eight in both finished objects does not by itself establish that the identical pieces were reused. The observed disassembly and rebuilding sequence supplies that part of the evidence. Keep the separated pieces visible and avoid mixing in another set. Ask the child to describe the process rather than merely name the finished objects. Rebuilding is not an example of every kind of material change: melting, dissolving, and chemical changes require other explanations. The activity also does not establish that all shapes are equally stable or useful. Those are design questions to test separately.

Plan the next activity

1. Record the first structure and count its parts.
2. Observe the disassembly and keep track of every piece.
3. Describe the new structure using the observation sequence.

Have a pair of students rebuild the same set into a third arrangement and prepare three labeled drawings: before, separated, and after. A partner should be able to follow the account without watching the rebuilding. If extra pieces are needed, record that change instead of claiming the original set was sufficient. Compare how rearrangement affects the object’s shape while the parts remain identifiable. The building lesson provides another starting point, and the teacher can connect this account with other Grade 2 investigations of material properties. A single block model does not cover the whole materials unit.