Short Blocks

# Maths Year 5 Spring Shape (B)

Each unit has everything you need to teach a set of related skills and concepts.

First time using Hamilton Maths?

The PowerPoint incorporates step-by-step teaching, key questions, an in-depth mastery investigation, problem-solving and reasoning questions - in short, everything you need to get started.

All the other resources are there to support as-and-when required. Explore at your leisure - and remember that we are always here to answer your questions.

## Unit 1 Recognise, measure and draw angles (suggested as 2 days)

### Objectives

Recognise, measure and draw angles
Unit 4: ID# 5507

National Curriculum
PofS
(ii) (iii)

Hamilton Objectives
47. Know angles are measured in degrees, estimate and compare acute, obtuse and reflex angles, draw and measure given angles.

### Planning and Activities

Day 1 Teaching
Using an online protractor, show how to align the protractor to read the angle. Point out how the numbers of degrees go both anticlockwise and clockwise; this is the case on many protractors! Measure angles of 90°, 180°, 270°. Show different angles for children to estimate then measure.
Group Activities
Use the in-depth problem-solving investigation ‘Nine-pin triangles’ from NRICH as today’s group activity.
Or, use this activity:
-- Accurately draw and measure angles.

Day 2 Teaching
Introduce acute, obtuse and reflex angles.
Launch ‘Angles’ from www.mathsisfun.com. Scroll down to 'Try it yourself' and move the top line of the angle anticlockwise to gradually increase it from 1° to 360°, asking children to watch the angle titles at the side. Draw some angles, and children classify them as acute, obtuse or reflex.
Group Activities
-- Classify angles as acute, obtuse or reflex through shape investigation.

### You Will Need

• IWB and internet access
• Whiteboards
• Rulers
• Protractors
• 1–6 dice

### Mental/Oral Maths Starters

Suggested for Day 1
24-hour time tease (simmering skills)

Suggested for Day 2
Quickly find complements to 100 (simmering skills)

### Worksheets

Day 1
Estimate and measure angles.

Day 2
Identify acute, obtuse and reflex angles.

### Mastery: Reasoning and Problem-Solving

• Draw an acute angle, estimate its size. Write your estimate. Then measure it. How close were you?
Repeat this for an obtuse angle.
• Draw a pentagon with two right angles and two obtuse angles. Can you draw a pentagon with three acute angles?
• True or False?
A quadrilateral could have two reflex angles.

In-depth investigation: Nine-pin Triangles
Draw triangles; measure and classify the angles of each triangle. Nine-pins Triangles from nrich.maths.org.

### Extra Support

Recognising acute, right and obtuse angles.

## Unit 2 Angle theorems; draw angles in polygons (suggested as 3 days)

### Objectives

Use angle theorems and draw polygons with specified angles
Unit 5: ID# 5521

National Curriculum
PofS (iii) (v)

Hamilton Objectives
46. Find unknown angles in triangles and rectangles; identify angles round a point and on a straight line, finding missing angles.
47. Know angles are measured in degrees, estimate and compare acute, obtuse and reflex angles, draw and measure given angles.

### Planning and Activities

Day 1 Teaching
Place two corners from an A4 page on a line, and then show that four right angles make a complete turn. Next, draw a straight line, then draw two straight lines to divide the 180° angle into three unequal angles. Measure these and show that they add to 180°.
Group Activities
-- Measure accurately to piece together angles on a straight line.

Day 2 Teaching
Establish that a full turn is 360° by asking children to turn through four right angles. Sketch an acute angle, and measure it with an IWB protractor. With the protractor still in place, ask children how big the reflex angle is that goes with the acute angle. Record, e.g. 75° + 285° = 360°. Repeat with other acute and obtuse angles.
Draw three lines that meet at a point. Ask children to measure two of the angles. Can you calculate the missing angle?
Group Activities
Use the in-depth problem-solving investigation ‘Olympic turns’ from NRICH as today’s group activity.
Or, use this activity:
-- Determine missing angles at point by finding a complement to 360°.

Day 3 Teaching
Agree that a polygon is a shape with straight sides, e.g. a hexagon, but not a circle. Display ‘Polygons’ images (see resources). Children describe each one with reference to their properties and the types or sizes of their angles. Ask children to sketch shapes with a range of angle properties, e.g. a triangle with no right angles and two angles the same, a pentagon with one reflex angle, etc.
Group Activities
-- Construct polygons; use them to create tessellations.

### You Will Need

• Interactive whiteboard and internet access
• ITP Calculating Angles (see resources)
• 180° and 360° protractors
• Semicircle angles (see resources)
• Rulers, scissors, glue, coloured paper (3 colours) & sugar paper
• IWB 360° protractor
• ‘Polygons’ images (see resources)

### Mental/Oral Maths Starters

Day 1
Find the complement to 180 (pre-requisite skills)

Suggested for Day 2
Properties of 2-D shapes (simmering skills)

Day 3
Estimating angles from nrich.maths.org (pre-requisite skills)

### Worksheets

Day 1
Find missing angles on a straight line.

Day 2
Find missing angles around a point.

Day 3
Draw polygons to given specifications.

### Mastery: Reasoning and Problem-Solving

• Draw a straight line divided into three acute angles. Measure two of the angles and calculate the third. Then measure it to check.
• Draw four angles around one point. Make the ‘missing’ angle 90 degrees. Measure and label the other three angles.
• The three angles inside a regular (equilateral) triangle are all 60°, so add to 180°. The four angles inside a regular quadrilateral (square) are all 90°, so add to 360°.
• The sum of the five angles inside a regular pentagon follows a pattern begun by the triangle and square. Can you calculate how big each one is?

In-depth investigation: Olympic Turns
Children explore photos of some Olympic sports that involve turns and angles. Olympic Turns from nrich.maths.org.

### Extra Support

One hundred and eighty!
Measuring angles using a protractor; Understanding that angles on a straight line add to 180°