TOPIC
1
Weight
Place Value
Strand: Measures
Number
Strand unit:Weight
unit: Place Value
Curriculum Objectives
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Select and use appropriate instruments of measurement.
Rename measures of weight.
Looking back: What the 5th class programme covered
1. Using appropriate instruments of measurement.
2. Estimating and measuring weight using appropriate metric units.
Maths skills used in this topic
1. Integrating and connecting: Make mathematical connections within mathematics itself,
throughout other subjects, and in applications of mathematics in practical everyday contexts.
Concrete materials
Weighing scales, weighing balance, labelled weights
Vocabulary
Load-bearing limit
Teaching points
1. Mass is defined as the quantity of matter a body contains. A body’s mass is
constant, whereas its weight will differ from planet to planet.
2. If carrying out class activities involving body weight bear in mind that some
children are very sensitive in this regard. Always best to look for volunteers to
be weighed.
Oral and mental activities
Target board 13:
Change each weight to either kg or g. Express each weight as a fraction and a
decimal number. Find 2 equivalent measures on the board.
Fans:
Call out a variety of fractions and children must show that fraction as either kg or g.
Topic suggestions
1. Estimating weight is a worthwhile and enjoyable activity and there are many estimating
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games. Divide your class into 2 teams and name something in the room. Team A has to
estimate the weight of the item and announce the estimate to the class. Team B has to say if
the item is lighter or heavier than the estimate announced by Team A. The weight of the item
is then measured. If Team B is right, it is awarded a point; otherwise Team A is awarded the
point. The incentive for Team A is to be as accurate as possible so that it is more difficult for
Team B to judge. For the next round, different item, Team B estimates and announces and
Team A judges whether the item is heavier or lighter.
2. Variation on above: You can have any number of teams. All teams estimate. The team that’s
closest is awarded 3 points, second closest 2 points and third 1 point, with a 5-point bonus
for any team that estimates exactly (or within 50g for heavy items).
Activity A
Discussion about weight and weightlessness
1. Where you might experience weightlessness. (swimming pool)
2. On which planets would you weigh more than on Earth?
3. On which planets would you weigh less than on Earth?
4. What are the benefits of being lighter?
5. What activities might be awkward in a weightless environment? (everything needs to be
tied down or it will float away, drinking through a straw, sports, etc.)
6. Use the factors in the picture to calculate weight on other planets (multiply a given weight
by the number corresponding to the planet), e.g. a baby weighing 7kg on Earth weighs 7 x
0.38 = 2.66kg on Mars and 7 x 2.36 = 16.52kg on Jupiter.
Differentiation
Lower attainers:
Separate activity sheet
Higher attainers:
1. Separate activity sheet
2. Look for weight records. Use the internet or other sources to find weight-related records:
heaviest apple ever grown (1.849kg, at date of publication), greatest weight lifted by
weightlifter, heaviest Easter egg, heaviest fish caught in Ireland, etc.
Topic
Topic
1. A van can safely carry up to 500kg of freight. Organise the following cargo into lots so that the van
1. Is each item lighter or heavier than 1kg. (Estimate – no need to measure)
(a) Computer keyboard
(b) Pair of glasses
(c) Hat
(d) New born baby
(e) DVD (disk)
(f) Loaf of bread
(g) Running shoe
(h) Full schoolbag
(i) Empty schoolbag
(j) Basketball
(k) Labrador (dog)
(l) Maths book
makes as few trips as possible:
2. Write the name of something whose weight you estimate to be
(a) Less than 500g
(b) Between 500g and 1kg
(c) Between 1kg and 2kg
(d) Between 2kg and 10kg
(e) Between 10kg and 50kg
(f) Heavier than 50kg
2. A bigger van can safely carry up to 800kg of freight. Organise the following cargo into lots so that
3. Can you figure out the missing weights?
the van makes as few trips as possible:
(a)
(b)
(c)
(d)
(e)
(f)
3. An even bigger van can safely carry up to 1,000kg of freight. Organise the following cargo into lots
so that the van makes as few trips as possible:
4. How many trips is a wheelbarrow likely to make to carry 360kg of debris, if it takes approximately
35kg on each trip? ______________
5. A pallet holds 6 dozen bags of flour, each weighing 7.5kg. A forklift’s limit is 820kg. How much
more weight could the forklift take before it exceeds its limit? ______________
4. Write these weights as kg using a decimal point.
(a) 1 12 kg
________
(d) 4kg
________
________
(c) 1kg 436g ________
(e) 40g
________
(f) 2kg 380g ________
(i) 3kg 14g
________
5. Write these weights as kg and g.
(b) 4.147kg ________
(c) 6.228kg
________
(d) 7.449kg ________
(e) 3.337kg ________
(f) 4.28kg
________
(g) 4.008kg ________
(a) 2.365kg ________
(h) 6.003kg ________
(i) 6.03kg
________
Name: _______________________________________
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Page 172: Weight
Date: ___________________
7. How much will a fisherman earn for a dozen lobsters if they weigh 1.35kg on average and the
buyer’s rate is €2.50 per kg? ______________
© Folens Photocopiables
(h) 3kg 140g ________
6. Paperweights are used to stop loose sheets of paper from falling off a desk. How much less than
1kg is a paperweight that weighs 22.5g? ______________
© Folens Photocopiables
(g) 2kg 38g ________
(b) 1 34 kg
8. A pallet holding 35 sacks of grain weighs 789kg. What is the weight of one sack of grain if the
pallet weighs 1 12 kg? ______________
9. Calculate the average weight of one person if the weights of four people are 86.5kg, 87.92kg,
79.65kg and 90.05kg ______________
Name: _______________________________________
Page 173: Weight
Date: ___________________
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Linkage
Number: Operations (adding and subtracting)
Integration
SESE Science: Life on other planets
Maths at home/parental involvement
Weight trail
Examine foodstuffs in the fridge or food press. Choose 8 items where the weight is shown on
the packaging. Note the name of the food and its unopened weight.
1. Use weighing scales to verify the weight of the items.
2. Which items are heavy but have a small size?
3. Can you find an item that’s light that has a large size?
4. If water is added to food during cooking, does it make it lighter or heavier?
5. Name some fruits and vegetables that are sold by weight.
6. What fruit and vegetables have no (or almost no) waste? (tomato, grapes, mushrooms, etc.)
7. Name some fruits and vegetables where some of the weight paid for is thrown away
(banana (skin), apple (core), peach (stone), orange (peel), etc.)
Notes
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