# Stage 2 – scaled number lines and temperature

Read a vertical number line; recognise and read a many-to-one number line; read a thermometer; use the markers on a drawn number line to read a numerical value

## Strategy

Students can:

• Read a vertical number line
• Recognise and read a many-to-one number line
• Use the markers on a drawn number line to read a numerical value

## Activities to support the strategy

In Stage 2 students are now introduced to temperature and using a scaled instrument in Length. For students to be able to read a scaled thermometer they need to have experience with using a real thermometer for many investigations (including thermometers with various many-to-one scaling). These conceptual understandings are built on from Stage 1 where students are required to use place value knowledge to order numbers on a number line and to use number lines with various numbers visible. This concept is then extended also into Stage 3 where students use a many-to-one scale on the x-axis and y-axis in data for creating line and column graphs.

### Activity 1 - reading number lines

Provide students with a range of number lines with many-to-one correspondence. This could be commercially made number lines, tape measures, 30 cm rulers, 1 m ruler, number lines students create or some the teacher creates for the task (some with each incremental mark equalling one, two, five and 10)

Ask students to find the same specific number on each number line e.g. find the number 7.

• Where is it?
• How did you work out where it would be?
• Did you use any other numbers/markers near the number?
• Is there a marker for number seven at all?
• How come they are at different point along each of our example number lines?
• Why do you think some number lines use a different scale?

Follow on from this activity by allowing students to make a number line with different many-to-one values.

### Activity 2 - telling the temperature

• Find a thermometer that has a clear scale (preferably one with only degrees Celsius).
• Have a class discussion about what the instrument is, what is it used for, how do we read it?
• This may prompt a discussion on negative numbers as well. How do we use the thermometer to measure temperature?

Spend time each day checking the thermometer and recording the temperature. Provide students with investigations around using the thermometer and recording their findings as part of a mathematics lesson or unit of learning.

## Resources

### Australian curriculum

ACMMG084: Use scaled instruments to measure and compare temperatures

### NSW syllabus

MA2-9MG: Use a thermometer to measure and compare temperatures to the nearest degree Celsius

### Links to other curriculum areas

Science and technology and HSIE