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Level Four > Geometry and Measurement

# Weighty Problems

Keywords:
Achievement Objectives:

Purpose:

This unit comprises 6 stations which involve the students solving problems which involve applying and interpreting aspects of mass. In addition one of the stations introduces the concepts of net and gross mass. The stations may be taken as whole class activities of they may be set up as activities that groups of students use throughout the week.

Specific Learning Outcomes:

select the appropriate standard unit of measurement for a specific application

measure masses with appropriate measuring devices

measure net and gross mass

Description of mathematics:

This unit provides students with the opportunity to extend their understanding of units of mass by exploring these within the context of problems.

Required Resource Materials:
Station 1: \$1, \$2 and 50c coins, scales (kitchen or balance but able to weigh in grams), Copymaster of the problem
Station 2: Copymaster of the problem
Station 3: Copymaster of the problem
Station 4: Copymaster of the problem, animal facts
Station 5: Copymaster of the problem, cans of food, can opener, balance or kitchen scales, calculators
Station 6: Copymaster of the problem, can of dog food, supermarket bags
Activity:

#### Station 1: A kilo of coins

You have won a prize which can be just one of the following:

1 kilogram of \$1 coins
A metre long of \$2 coins (lying flat and touching)
2 kilograms of 50c coins

#### Station 2: Largest Lasagne

The largest lasagne was made for the Dublin Spring Show in Ireland.
It weighed 1637.3 kg and measured 15.24 m x 1.52 m.

How many people do you think it could feed?
Show how you arrived at your estimate.

#### Station 3: Weighing Tonnes

Konsihiki is the largest sumo wrestler in the world with a mass of 226 kg. How many Konishiki’s do you need to weigh a tonne!

Make a table of tonne weights using objects in the classroom. Remember that 1000 kg is a tonne.

 Object Mass Number in a tonne Konsihiki 226 kg

#### Station 4: Jumbo facts

Find out facts about the mass of very large animals and make a report about these for the class. To get you started here are some facts about the African elephant.

The African elephant is the biggest animal on land. Fully grown the male can be 7 metres long, 3.2 metres tall at the shoulder and have a mass of 6500 kg. Its tusks can weigh as much as 100 kg each. The largest pair of tusks on record are in the British Museum and weigh 133 kg each. Facts can be found be seaching the internet, Wellington Zoo has information on animal sizes on www.wellingtonzoo.com
compare animal weights to their own weights
what combination of animals could be equal to the elephant's weight?
If the zoo's scales could hold a tonne, what animals could go on them?

#### Station 5: Net and Gross Weights

Check the label of each can. What mass is stated on each?
Check the mass of each can on the scales. What did you find?
Open the can and measure the mass of the contents. What did you find?
What do you think that the terms net mass and gross mass mean?
Why do you think that packages state the net mass?
With a variety of cans and food items ask: What percentage of this item is packaging?

#### Station 6: Frank’s arms

Counting on Frank by Rod Clement (1990; Harper Collins Publishers: Sydney ) has some great ideas for measurement investigations. One of the ideas introduced in the story is about Frank carrying a trolley load of cans to the supermarket.

How heavy do you think his load is?

How many cans are you able to carry in a supermarket bag? How did you work this out?

Note: there are other activities associated with Counting on Fran at the following link:

http://www.nzmaths.co.nz/resource/counting-frank

AttachmentSize
WeightyProblemscm1.pdf76.2 KB
WeightyProblemscm2.pdf65.19 KB
WeightyProblemscm3.pdf86.8 KB
WeightyProblemscm4.pdf52.27 KB
WeightyProblemscm5.pdf75.35 KB
WeightyProblemscm6.pdf70.42 KB

## Supermarket Shopping

In this unit we introduce the kilogram as a standard unit of measurement using the context of Supermarket shopping. We develop our understanding of the "feel" of a kilogram by making our own kilogram weights.

## Great Grams

This unit comprises 5 stations which develop our concept of the "feel" of a gram. The stations may be taken as whole class activities or they may be set up as activities that groups of students use throughout the week.

## Weighing Stations

In this unit students work at a variety of stations involving practical measuring tasks. Estimation skills and the ability to measure accurately using kilograms and grams are developed.

## Making Benchmarks - Mass

In this unit we will explore the idea of having Benchmarks of 1 kilogram and 1/2 kilogram or 500 grams to aid in estimating the mass of given objects.

## Oranges L4

In this unit we focus on selecting appropriate units for measurement in practical situations.  We ask the students to justify the instrument they have used for the degree of accuracy required in their measurements.