Algorithm

Algorithm

An algorithm is a set of instructions
that can be followed step by step to

solve a particular problem.

FLOWCHARTS &
VARIABLES

Y6 CAMBRIDGE UNIT 4

OVAL

DO YOU REMEMBER THE NAME OF THESE
SHAPES?

PARALLELOGRA
M

RECTANGLE

DIAMOND

START/STOP

DO YOU REMEMBER THE MEANING OF THEM IN
FLOWCHARTS?

INPUT/OUTPU
T

PROCESS

DECISION

An oval represents start or stop in
a program.

We will use a green oval for the
start and a red oval for the stop.

START/STOP

START/STO
P

STOP

START

An arrow is used to connect the
shapes. It shows the path to follow.

We will use a black arrow.

ARROW

ARROW

A parallelogram represents an input or
output.

We will use a light blue parallelogram forr
the input and a dark blue parallelogram for
the output.

For example, an input can be a user
entering information and an output can be a
message displayed on a screen.

INPUT / OUTPUT

INPUT /
OUTPUT

OUTPUT

INPUT

A rectangle represents a process.

We will use a purple rectangle for a
process.

For example, a process can be a
formula to calculate a value.

PROCESS

PROCESS

PROCESS

A diamond represents a decision
point between two or more paths in a
flowchart. We will use a yellow
diamond for a decision.

For example, this step may ask a
question and the result can be either
true or false, or yes or no.

DECISION

DECISION

DECISION

WHAT IS A
VARIABLE?

DO YOU KNOW?

VARIABLE

A variable is used for storing
data.
A variable is like a box to store text, numbers and
data.

VARIABLE

A variable is used for
storing data.

A variable is like a box to
store text, numbers and data.

Each ice lolly is made in the same way. The algorithm for making the ice
lolly would be the same each time. The only thing that changes is the type
of fruit used. This is the variable.

Pour water into the lolly mould.

Add fruit.

Place lid firmly on end of mould.

Leave in freezer for 24 hours.

Remove lolly from mould.

VARIABLE ACTIVITY

Could you try naming the variables based on what
you see?

Flowchart

Pseudocode

Let’s try an
instruction

How do you
calculate an

area?

Square

Length

Length
To find the area of a square

area = length * length

PSEUDOCODE?

START
length = INPUT
area = length * length
OUTPUT area
STOP

Try this activity on your own