More measures
Mass and temperature
Mass tells us how heavy or light something is. Temperature tells us how hot or cold something is. Let's learn to measure both.
What is mass?
Mass tells us how heavy or light something is. Mass does not depend on size. There can be big light objects and small heavy objects — a balloon is big but light.
Grams and kilograms
The mass of a light object, such as a pencil, is measured in grams. A heavier object, such as a bag of flour, is measured in kilograms. We can compare masses with a balance scale — the heavier side goes down.
Halving in recipes
If you want to make fewer of something, you can halve the amounts. For 5 biscuits instead of 10, halve each ingredient. Half of 100 grams of flour is 50 grams.
Temperature
Temperature tells us how hot or cold something is. We measure it with a thermometer, in degrees Celsius (°C). The hotter it is, the higher up the scale the colour goes. Higher temperatures are warmer; lower temperatures are cooler.
Worked examples
Grams or kilograms?
- Is the object light, like a pencil? Use grams.
- Is the object heavy, like a bag of flour? Use kilograms.
Answer: Light objects use grams; heavy objects use kilograms.
Halving a recipe
- The recipe makes 10 biscuits with 100 grams of flour.
- 5 is half of 10, so halve the flour.
- Half of 100 is 50.
Answer: For 5 biscuits you need 50 grams of flour.
Which is warmer?
- One town is 26°C and another is 10°C.
- Higher temperatures mean it is warmer.
Answer: The town at 26°C is warmer.
Where you see this in real life
- Weighing flour in kilograms to bake a cake.
- Weighing a light pencil in grams.
- Reading a thermometer to see how hot it is outside.
- Choosing warm clothes when the temperature is low.
Key words
- Mass
- How heavy or light something is.
- Gram
- A unit for measuring the mass of light objects.
- Kilogram
- A unit for measuring the mass of heavy objects.
- Balance scale
- A tool that compares masses — the heavier side goes down.
- Temperature
- How hot or cold something is.
- Thermometer
- A tool that measures temperature in degrees Celsius (°C).