1. Mass Unit of Study: Measure and Estimate Volume and Mass Global Concept Guide: 1 of 2

2. Content Development  Students need to be able to estimate and measure masses of objects using the standard unit grams (g) and kilograms (kg).  Students do not need to be able to convert between units.  Students need to be able to solve one-step word problems involving masses within the same unit. Problems will not include two different units.  Problems will not include multiplicative comparison problems.

3. Content Development  Students need to understand…  that larger units can be subdivided into equivalent units (partitions).  that the same unit can be repeated to determine the measure (iteration).  the relationship between the size of a unit and the number of units needed (compensatory principal).  These standards do not differentiate between weight and mass. Technically, mass is the amount of matter in an object. Weight is the force exerted on the body by gravity. On the earth’s surface, the distinction is not important (on the moon, an object would have the same mass, would weigh less due to the lower gravity).  Many of the topics in the unit align with science standards. Students should be familiar with topics in this unit from science class.

4. Content Development  Misconception Alert: Students may confuse the amount of objects or size of objects with its weight. For example, if asked which weighs more, a pound of feathers or a pound of bricks, students may answer a pound of bricks. This is due to confusion concerning the weight or attributes of the objects being measured rather than an understanding of standard units of measure.  Allow students to hold gram and kilogram weights in their hand to use a s a benchmark.  Students should estimate masses before actually finding the measure.

5. Day 1  For Day 1 students will be comparing weights of different objects using a balance scale and non-standard units.  Through discovery they will see that if the non-standard unit is larger, it will take less of them to equal the object’s mass.  How Many Paper Clips? Works great for this lesson. Students realize that as they use larger paperclips it takes less of them to equal the mass of the object. How Many Paper Clips?  Make sure students get plenty of hands-on experience weighing objects.

6. Day 2  During Day 2 students should move from non-standard to standard units of measure.  Students should see why we must have standard units.  Make sure students get plenty of hands-on experience weighing objects.  Setting the Standard is a good lesson Setting the Standard for Day 2. Students weigh fruit and with paperclips and with gram weights. They realize that they need to have a standard unit in order to compare results.

7. Day 3  During Day 3 students should practice estimating mass and establishing a concrete benchmark of about what weighs 1 kilogram (kg).  Allow students to identify objects in the room that weigh about one kilogram (kg).  Making a Kilogram is a good activity to Making a Kilogram build this understanding.  Make sure students get plenty of hands-on experience weighing objects.

8. Day 4  During Day 4 students should establish a benchmark of what weighs about 1 gram (g). A large paperclip weighs about a gram.  Students should practicing estimating the mass of objects and then weighing them. They should compare their actual masses to their estimates.  Make sure students get plenty of hands-on experience weighing objects.  Worth the Weight is a good lesson to give students these opportunities. Worth the Weight

9. Enrich/Reteach/Intervention Reteach  Create an anchor chart showing grams and kilograms and various examples of what weighs each amount.  Have students make estimates with peers. Enrich  Have students estimate how many items, such as apples, it would take to make 1kg, 10kg.  Have students find objects around the room that weigh 5g or 5 kg.