# Cross-curricular mastery: maths and science in Year 3

**Editor’s note:** This post is part of our Cross-curricular mastery series. Here, you’ll find tips and advice to help you make the most of the links between maths and other subjects.

Weaving other subjects into your lessons is a great way for learners to see how useful maths is. It’s particularly helpful for Year 3 because that’s when children are first introduced to KS2 and the complexity of work increases which means they need to have solid contexts to support their understanding.

Here’s how to consolidate maths skills within science lessons in Year 3. The lesson ideas below are:

- Ordered chronologically based on the
**Maths — No Problem!**long term planning for Year 3 - Cover all of the knowledge-based objectives in the science curriculum and the maths objectives in the areas stated

## Animals, number and place value (Autumn Term)

Children tend to love animals. They are fascinating to look at but even more fascinating when you start to pick apart the similarities and differences between species. Take the opportunity to capture the children’s interest in animals by showing them how to use place value.

### Lesson 1: Animals and their calories

**Maths objectives**

- Compare and order numbers up to 1,000

**Science objectives**

- Identify that animals, including humans, need the right types and amount of nutrition, and that they cannot make their own food; they get nutrition from what they eat

Think about calories! How many calories does the average human child need in a day? Give the children the data for the number of calories different animals need every day and ask them to order it from most to least. Can they think about why a hamster may need less calories than a human or a rat? Talk about what calories are and why we need them. Point out that not all animals can make their own food.

### Lesson 2: Animals, bones and muscles

**Maths objectives**

- Identify, represent and estimate numbers using different representations

**Science objectives**

- Identify that humans and some other animals have skeletons and muscles for support, protection and movement

Show the children a human skeleton and ask them to estimate how many bones there are, then tell them an adult human skeleton has 206 bones and over 700 muscles. Discuss what bones and muscles do and why we need them. Ask the children to make posters showing different ways to represent those numbers. Can they do the same for any other animals?

## Plants and Measurement (Spring Term)

Plants can grow very quickly, allowing children to then use measurement for a real life purpose. Plants also come in lots of different shapes and sizes, which means the numbers vary. This makes them perfect for KS2 pupils who should be working fluidly with 3-digit numbers as well as with measurements such as millimetres, centimetres and metres.

### Lesson 1: Measuring flowers

**Maths objectives**

- Measure, compare, add and subtract lengths, including metres, centimetres and millimetres

**Science objectives**

- Identify and describe the functions of different parts of flowering plants, for example roots, stem, trunk, leaves and flowers

Get the children to dissect a flower into its different parts then write a fact file for each part of the flower, including the length of each part in millimetres and centimetres. Can they add the measurements together to find the total length of every part of the flower? Can they compare it to another flower or a small tree and find the difference between the lengths?

### Lesson 2: What do plants need to grow

**Maths objectives**

Measure, compare, add and subtract mass, including kilograms and grams, and volume/capacity, including litres and millilitres

**Science objectives**

- Explore what plants need for life and growth, for example air, light, water, nutrients from the soil and room to grow.
- Discuss how these vary from plant to plant

Look at a variety of different plants and compare the volume of water that is needed to keep them alive. What else is needed to keep plants alive? Compare the amount of nutrients, the space needed for their roots and see if these have any link to the mass of the plants.

### Lesson 3: How plants transport water

**Maths objectives**

- Estimate and read time with increasing accuracy to the nearest minute
- Record and compare time in terms of seconds, minutes and hours
- Use vocabulary such as o’clock, a.m. and p.m., morning and afternoon, noon and midnight

**Science objectives**

- Investigate the way in which water is transported within plants

Tell children they are going to put a few different plants in inky water. Ask them to estimate what will happen after seconds, minutes, hours and days. Then do the experiment and ask the children to record what happens within those timeframes. Can they write up their findings as a diary using the mathematical language linked to time?

### Lesson 4: The life cycles of plants

**Maths objectives**

- Know the number of seconds in a minute and the number of days in each month, year and leap year
- Calculate and compare durations of events, for example, how long it takes to complete particular events or tasks

**Science objectives**

- Explore the role flowers play in the life cycle of flowering plants, including pollination, seed formation and seed dispersal

Have children research the life cycle of plants. Get them to choose two plants and make timelines of events, beginning when the seed is planted and ending when the seeds are dispersed. Use the data they collect to compare how long each part of the cycle takes for both plants and look at what happens over the course of seconds, days, months and the year.

## Light and statistics (Spring Term)

Light is a fantastic subject to pair with statistics because by using data loggers, light becomes measurable. That will give children a new fascination with statistics because they will be able to see concrete data about something that seems intangible in everyday life.

### Lesson 1: Measuring light

**Maths objectives**

- Interpret and present data using bar charts, pictograms and tables

**Science objectives**

- Understand that to see things, we need light, and dark is the absence of light
- Notice that light is reflected from surfaces
- Recognise that light from the sun can be dangerous and there are ways to protect our eyes

Using data loggers, have the children measure the amount of light in the room with the lights on and off. Turn off the lights and talk about whether they can still see in the dark. Ask them to carefully observe the room to try to discover where the light is getting in. Make dark boxes — shoe boxes covered in duct tape with a small peep-hole — and get the children to look inside. Can they see true darkness? Can they measure light bouncing off different materials? Explain why it’s important not to look directly at the sun. Measure the light from the sun with the data logger. Use the measurements collected during this exploration to make bar charts, pictograms and tables before drawing conclusions about reflective materials, the dangers of the sun and what darkness is.

### Lesson 2: Measuring shadows

**Maths objectives**

- Interpret and present data using bar charts, pictograms and tables

**Science objectives**

- Recognise that shadows are formed when the light from a light source is blocked by an opaque object
- Find patterns in the way shadows change

Make a sundial using a stick and mark where the shadow is every hour. Measure the distance between the points of the shadow and create a table showing how far it moves. Interpret the data, thinking about the accuracy of the measurements and what the data show about the movement of the sun. Ask the children to predict what would happen if they used a different object. Can they use the data to recreate the sun’s movements in the class with a torch and an object?

## Magnets and Fractions (Spring Term)

Magnets used in schools tend to be quite clearly split in half, usually with a blue and red side to illustrate the two poles, so why not continue this natural link by looking at other fractions as well?

### Lesson 1: Marking distance with trains

**Maths objectives**

- Count up and down in tenths
- Recognise that tenths arise from dividing an object into 10 equal parts and in dividing one-digit numbers or other quantities by 10

**Science objectives**

- Compare how things move on different surfaces
- Notice that some forces need contact between 2 objects, but magnetic forces can act at a distance

Explore different forces by pushing, pulling and using a magnet to push a toy train with magnetic attachments down a counting stick. Instead of measuring the distance, measure how many tenths the train has moved from different forces. What if you add another metre stick? Where will the tenth markers have to go?

### Lesson 2: Exploring magnetism

**Maths objectives**

- Recognise, find and write fractions of a discrete set of objects, unit fractions and non-unit fractions with small denominators

**Science objectives**

- Observe how magnets attract or repel each other and attract some materials and not others
- Compare and group together a variety of everyday materials on the basis of whether they are attracted to a magnet, and identify some magnetic materials

Give children magnets and place a variety of objects made of different materials on every table. Ask them to group the objects into magnetic and non-magnetic, and then talk about what fraction of materials are magnetic compared with non-magnetic.

### Lesson 3:

**Maths objectives**

- Use diagrams to show equivalent fractions with small denominators
- Compare and order unit fractions and fractions with the same denominators

**Science objectives**

- Describe magnets as having two poles
- Predict whether two magnets will attract or repel each other, depending on the placement of the poles

Show children the magnets and how they attract and repel one another. Ensure they understand that one half of the magnet will be north-facing and the other half will be south-facing. If you have two magnets, two quarters of the poles are north and south. What if you have 12 magnets? What if on an alien planet the magnets have three poles, or four poles? Draw diagrams to illustrate the equivalent fractions.

Year 3 is an important year for children because it often involves a big transition to a different school or a change in timetable that reflects the difference between KS1 to KS2. Adding context to maths through the science curriculum can help ground the children and make them feel more secure in their knowledge during what can be a challenging time in their school lives.