Indiana Grade 2 Science

Use the same pieces to explain how a new object is built

Compare a tower and bridge made from the same classroom blocks, record what changes, and explain an original Grade 2 matter activity.

The Indiana science standards directory links grade-specific documents for the 2023 Indiana Academic Standards. Use the 2023 Indiana Academic Standards: Grade 2 Science for the selected performance expectation and its complete supporting information. This activity selects a Grade 2 expectation. It is one part of a science course, not a complete curriculum.

What changes when twelve blocks become a bridge?

A teacher provides twelve large classroom building blocks. Students count and describe them, arrange them as a tower, and make an observation drawing. They take the tower apart without breaking any block and use all twelve pieces to construct a short bridge model on the table. The example record describes a planned classroom comparison; students replace it with their own observations when they carry out the activity.

Explain the evidence or model

The whole object changes from a tower to a bridge, while the set of pieces stays the same. Counting twelve blocks before disassembly, after disassembly, and after rebuilding provides evidence that the pieces were retained. A student should also describe their arrangement: a tower places pieces upward, while the bridge model connects supports across a gap. Count alone does not show the design, and a drawing alone may hide a piece behind another piece. Combine a count, a description, and an observation drawing. An explanation can state that taking an object apart allows its pieces to be arranged into a different object without claiming that every possible design will be stable.

What to check in the explanation

The number twelve refers to blocks, not centimeters of height or the bridge’s ability to support weight. A taller arrangement does not require additional material if the same pieces are reorganized. Conversely, if two pieces are set aside, the record should say ten pieces in the new object and two unused, rather than silently count all twelve as part of it. This activity changes the arrangement of familiar pieces; it does not demonstrate every change in matter or a chemical reaction. The selected expectation calls for observations supporting an account, so an adult’s completed model is less useful if children never observe its disassembly.

Plan the next activity

1. Count and describe the pieces before building the first object.
2. Observe the object being taken apart and account for every piece.
3. Rebuild, draw the new arrangement, and explain what stayed the same.

Ask a partner to rebuild the first design from a drawing and compare the result with the original record. Add a clearer drawing or label when the instructions leave an important arrangement uncertain. Then choose a third design using the same set and explain which features changed again. Keep models at table height and use teacher-approved blocks; this is not a test of a bridge carrying a person or a heavy load. A later investigation could compare how different shapes fit a purpose, but label that as a new question. Rebuilding one block set supports this selected expectation without covering the whole Grade 2 matter unit.