YEAR 4 MATHS FOCUS
MEASUREMENT AND GEOMETRY
Angles
Learning Experiences
Angles
ANGLES
OUTCOME
A student:
MA2-16MG: identifies, describes, compares and classifies angles
| TEACHING POINTS | A simple ‘angle tester’ can be made by placing a pipe-cleaner inside a straw and bending the straw to form two arms. Another angle tester can be made by joining two narrow straight pieces of card with a split-pin to form the rotatable arms of an angle. |
LANGUAGE | Students should be able to communicate using the following language: angle, arm, vertex, right angle, acute angle, obtuse angle, straight angle, reflex angle, angle of revolution. |
| The use of the terms ‘sharp’ and ‘blunt’ to describe acute and obtuse angles, respectively, is counterproductive in identifying the nature of angles. Such terms should not be used with students as they focus attention on the external points of an angle, rather than on the amount of turning between the arms of the angle. |
EXPECTATIONS OF ATTAINMENT
Compare angles and classify them as equal to, greater than or less than a right angle (ACMMG089) | compare angles using informal means, such as by using an ‘angle tester’ |
| recognise and describe angles as ‘less than’, ‘equal to’, ‘about the same as’ or ‘greater than’ a right angle {Literacy} | |
| classify angles as acute, right, obtuse, straight, reflex or a revolution {Literacy} | |
| – describe the size of different types of angles in relation to a right angle, eg acute angles are less than a right angle {Communicating} | |
| – relate the turn of the hour hand on a clock through a right angle or straight angle to the number of hours elapsed, eg a turn through a right angle represents the passing of three hours {Reasoning, Critical and creative thinking} | |
| identify the arms and vertex of the angle in an opening, a slope and/or a turn where one arm is visible and the other arm is invisible, eg the bottom of an open door is the visible arm and the imaginary line on the floor across the doorway is the other arm | |
| create, draw and classify angles of various sizes, eg by tracing along the adjacent sides of shapes | |
| – draw and classify the angle through which the minute hand of a clock turns from various starting points {Communicating, Reasoning} |
Learning Experiences
To be added