(PreK-2) E3

Science Curriculum Preview Committee Clarification of Learning Results

Revised 04/07/04

5-8

E1: Predict and test whether objects will float or sink based on a qualitative and quantitative understanding of the concepts of density and buoyancy.

Curriculum Organizing Questions

What is density?

How are floating and sinking related to density?

How can you measure the density of a liquid? regular solid? irregular solid?

How can you use the formula d = m/V to find the density of an object?

How can you use density to identify a substance?

Elaboration
Students should understand mass and volume before studying density. This indicator is an excellent place to work on measurement tools (graduated cylinders, balances) and metric units. The focus is not on manipulating the formula but on practical applications of sinking and floating. Students should be exposed to the effects of solids in other liquids than water.

Specific Ideas

Equal volumes of different substances usually have different weights. Benchmarks 4D2

Substances have characteristic properties, like density, which are independent of the amount of the sample. NSES B1a

By the end of 8th grade, students should be able to:

determine what unit an answer should be expressed in from the units of the computation. Benchmark 12B7

round off the results of calculations to reasonable represent the precision of the inputs. 12B8

use, interpret, and compare numbers in several equivalent formats such as fractions and decimals. 12B2

read analog and digital meters on instruments used to measure length, volume, and weight. 12C3

Developmental & Instructional Implications
In an Australian study, 80% of 11 year olds had misconceptions about volume. Students are also likely to confuse "weight" and "density". At this stage of development, students should not be expected to have a correct model of density. This concept is slow to develop and will benefit from multiple exposures in as many settings as possible over the grade span. Driver p. 78

It can be tempting to introduce atoms and molecules so that particles can be used as an explanation of properties. However, use of such terminology is premature for these students and can detract from the udnerstandings that can be gained from focuisng on observation and description of macroscopic properties. NSES Standard B p. 149.

Examples

implications for water currents, air masses, rock cycle

Back to Big Ideas Grid E Back to Standard E Back to Index

Curriculum Organizing Questions	What is density? How are floating and sinking related to density? How can you measure the density of a liquid? regular solid? irregular solid? How can you use the formula d = m/V to find the density of an object? How can you use density to identify a substance?
Elaboration	Students should understand mass and volume before studying density. This indicator is an excellent place to work on measurement tools (graduated cylinders, balances) and metric units. The focus is not on manipulating the formula but on practical applications of sinking and floating. Students should be exposed to the effects of solids in other liquids than water.
Specific Ideas	Equal volumes of different substances usually have different weights. Benchmarks 4D2 Substances have characteristic properties, like density, which are independent of the amount of the sample. NSES B1a By the end of 8th grade, students should be able to: determine what unit an answer should be expressed in from the units of the computation. Benchmark 12B7 round off the results of calculations to reasonable represent the precision of the inputs. 12B8 use, interpret, and compare numbers in several equivalent formats such as fractions and decimals. 12B2 read analog and digital meters on instruments used to measure length, volume, and weight. 12C3
Developmental & Instructional Implications	In an Australian study, 80% of 11 year olds had misconceptions about volume. Students are also likely to confuse "weight" and "density". At this stage of development, students should not be expected to have a correct model of density. This concept is slow to develop and will benefit from multiple exposures in as many settings as possible over the grade span. Driver p. 78 It can be tempting to introduce atoms and molecules so that particles can be used as an explanation of properties. However, use of such terminology is premature for these students and can detract from the udnerstandings that can be gained from focuisng on observation and description of macroscopic properties. NSES Standard B p. 149.
Examples	implications for water currents, air masses, rock cycle