# Generalising patterns using tenths or hundredths

Lesson

You may have started looking at how to write rules to describe patterns with decimals and fractions. A general rule uses pronumerals, which are letters used to represent unknown values.

#### Worked examples

##### Question 1

Complete the pattern by adding $0.3$0.3 each time.

1.  $0.4$0.4 $\editable{}$ $\editable{}$ $\editable{}$ $\editable{}$ $\editable{}$
2. If $b$b belongs to the same pattern, what is the next number?

##### Question 2

Consider the following pattern.

1. What is the pattern?

 $6.3$6.3 $5.9$5.9 $5.5$5.5 $\editable{}$ $\editable{}$ $\editable{}$

The numbers are decreasing by $4$4.

A

The numbers are decreasing by $0.4$0.4.

B

The numbers are decreasing by $40$40.

C

The numbers are decreasing by $0.04$0.04.

D

The numbers are decreasing by $4$4.

A

The numbers are decreasing by $0.4$0.4.

B

The numbers are decreasing by $40$40.

C

The numbers are decreasing by $0.04$0.04.

D
2. Now complete the pattern.

 $6.3$6.3 $5.9$5.9 $5.5$5.5 $\editable{}$ $\editable{}$ $\editable{}$
3. If $b$b belongs to the same pattern, what is the number after $b$b in the pattern?

##### Question 3

Complete the pattern by subtracting $\frac{1}{10}$110 each time.

1.  $\frac{6}{10}$610​ $\editable{}$ $\editable{}$ $\editable{}$ $\editable{}$ $\editable{}$
2. If $c$c belongs to the same pattern, what is the next number?

### Outcomes

#### NA4-2

Understand addition and subtraction of fractions, decimals, and integers

#### NA4-9

Use graphs, tables, and rules to describe linear relationships found in number and spatial patterns