North Dakota Grade 2 Science

Take Apart and Rebuild with the Same Pieces

Observe how one set of blocks can make different objects in North Dakota Grade 2 science, with a worked account, state references, lessons, and quizzes.

The current NDDPI science page links the North Dakota Science Content Standards, February 2019, revision 2 December 2019, using the actual North Dakota performance-standard codes and clauses. This activity selects a Grade 2 objective in the North Dakota document. It is one part of a science course, not a complete curriculum.

The state document explains that local districts use the standards to develop their curriculum. It includes science and engineering practices, crosscutting concepts, and North Dakota connections. Read the complete grade objectives alongside the school’s course, including investigations, models, evidence, and explanations. The general lesson library below may include review or enrichment beyond this grade’s course. This original activity is a focused starting point, not a complete curriculum crosswalk.

What stays when a wall becomes two towers?

An adult provides six classroom building blocks: three red and three blue. First build a low wall using all six. Draw the wall and count the blocks by color. Take it apart, keeping every block on the tray, and use the same six blocks to build two small towers. Draw the second arrangement and compare it with the first. Use your observations to explain what changed and what stayed the same. The record below is an invented example of a child’s count; check your own construction rather than claim these are your results.

Explain the evidence or model

The example records three red and three blue blocks in the wall, and the same three red and three blue blocks across the two towers. The blocks’ arrangement and the resulting objects change, while the set of pieces remains the same. Taking the wall apart separates its blocks; rebuilding combines those existing pieces in a new way. A useful account describes the first object, the disassembly, and the new objects and uses both drawings and counts as evidence. A different shape does not show that new blocks appeared. Counting the colors helps check that the same supplied set was used, but a drawing and count alone do not measure each block’s mass. Explain the observed rebuilding without inventing a weighing result.

What to check in the explanation

A taller-looking object does not necessarily contain more pieces. Compare all pieces used across both towers, not one tower with the whole wall. If a block is missing from the tray, check where it went before completing the account. Blocks keep their identity in this rebuilding task; it is not an example of producing a new substance. Use teacher-approved pieces and record actual observations separately from the supplied example.

Plan the next activity

1. Draw the first object and identify all pieces.
2. Take it apart and rebuild using the same complete set.
3. Explain the changed arrangement with observations from both objects.

Use the same teacher-approved set for a third construction. Draw it, then ask a partner to explain how its pieces relate to the first two. Identify a feature that changed and evidence that the set stayed the same. A real classroom account should show the learner’s own observations rather than copy the invented record.