# Paint It!

Purpose

In this unit we measure small quantities of paint accurately to produce our own colour range. We also think about colour and where it comes from.

Specific Learning Outcomes
• accurately measure volumes up to 10 ml
• estimate amounts of constituent paint used in given mixtures, up to 10ml
• describe the effect of adding incremental amounts of white paint to an existing colour.
Description of Mathematics

### A description of the mathematics explored in the unit

In this unit students are reading scales, and developing an understanding of the size of a mL by working with these measurements. They compare volumes using phrases such as “less than” greater then” and “equal to”.

### A description of the science explored in this unit

The concepts covered in this unit are outlined more fully in "Seeing Colours, The Spectrum, the Eye and the Brain", number 11 in the Building Science Concepts series.

The main idea covered is that the colours of objects come from their reflection and absorption of different parts of the spectrum of colours in light.

Associated Achievement Objective

Science, Physical World AO1: explore, describe, and represnt patterns and trends for everyday examples of physical phenomena such as movement, forces, electricity and magnetism, light, sound, waves and heat.

Required Resource Materials
Tempera paint in primary colours: red, blue, yellow and white. Mix to a runny consistency

Droppers to measure small amounts up to 5mL

Paint brushes

Paper

Samples of paint charts

Key Vocabulary

colour, light, absorption, reflection, combinations, consistency, accuracy, scale, formula, millilitres, litres

Activity

#### Introduction, Session 1

1. Brainstorm students’ ideas about colour.
What can you tell me about colour and how we see it?

What do we need to be able to see colour? (light)
How are colours different in different lights?
How can we create new colours?
2. Explain that this week the students will become paint designers and technicians, creating their own new colour range of paints.
3. Allow the students time to experiment with mixing colours of paint to create new colours, focusing on the variety of combinations possible.
4. Have students share some of the colours they have created and describe how they achieved the effect.
5. Show the samples of paint charts as examples of the types of charts students will produce so customers will be able to choose the colours they require.
6. Discuss the need for consistency.
If customers were going to purchase our paints they would need to be the same every
time.
How will we achieve this?

What units of measurement will we need to use?
7. Introduce the droppers as a way to accurately measure small quantities of paint and outline the unit of one mL as one thousandth of a litre.
8. Allow students time to practise measuring small amounts, reinforcing the importance of being accurate and reading the scale carefully.

#### Exploring, Sessions 2-4

Over the next few sessions have students develop 2-3 base colours and record the “secret formula” for these colours. For example, Groovy Green is made from 4ml of blue and 2.5ml of yellow. As they develop base colours they can present these in a paint chart type presentation, developing lighter hues by adding a constant amount of white and naming these colours also. For example, Avocado can be made from 4ml blue, 2.5ml yellow and 1 ml white, Apple can be made from 4ml blue, 2.5ml yellow and 2 ml white.

As students work, reinforce the importance of accurate measurement. Have students reconstruct the colours others have created, using the secret formulae. Are the colours the same? Why? Why not?

1. Discuss the new colours being created:
What new colours have we made?

Does it make a difference if the colours we mix are light or dark to start with?
If so, how are the resulting colours affected?
2. Explain that light is made up of lots of different colours. Most surfaces around us absorb light but not all surfaces absorb all the colours of light. What we see is the part of white light that is not absorbed by the surface.
What colours make up white light?

What colours are reflected when we see a red object?
What colours are absorbed?What colours are reflected when we see a blue object?
What colours are absorbed?
3. Have students calculate the formula for larger quantities of paint. For example:
If I wanted to order 2 litres of paint for my kitchen what would the secret formula be?
What if I wanted 6 litres for my dining and living area?

#### Reflecting, Session 5

1. Present the students with a colour you have created and named, for example Awesome Orange.
2. Explain that this is one of the colours another paint company has created and they need to discover the secret formula as one of our loyal customers has requested it.
3. Allow the students time to experiment with paints to find the formula. As they work compare the results and the mixtures they have used. For example:
Why is your orange lighter/darker than Awesome Orange? What do you need to change? Why? What amounts of paint will you try now?
4. As a conclusion share the secret formula for Awesome Orange and have students share their finished paint charts with the group.