Number patterns and rules

Write rules with words and letters.

Tables pushed together for a wedding feast.

Tables and chairs

1 table seats 6. 2 tables pushed together seat 10. 3 tables seat 14. Can we predict how many seats for 20 tables?

Term-to-term

The term-to-term rule is “add 4”. This helps find the next term. But 20 tables would take a long time!

Position-to-term

Each table gives 4 seats, plus 2 at the ends. Seats = 4 × tables + 2. For 20 tables: 4 × 20 + 2 = 82 seats.

Using letters

Let t be the number of tables and s the seats. s = 4t + 2 is an expression with a variable. Now we can find s for any t.

Patterns with fractions and place value

Patterns can use fractions and decimals: 0.2, 0.4, 0.6 … Place-value patterns: 3 × 2 = 6, 3 × 20 = 60, 3 × 200 = 600. Use a calculator to explore: start at 5 and keep adding 25. What do you notice?

What I learnt

I can describe term-to-term and position-to-term rules.
I can use letters to write rules.