x 3 x + 3 = 8 Come play with numbers!
Patterns & next terms

What repeats if we look carefully?

# Spot the pattern A sequence: `3, 6, 9, 12, …` Each term adds 3. That is a **rule**. Another: `2, 4, 8, 16, …` — multiply by 2 each time. ## Ask 1. What do I do to get the next term? 2. Does the same rule work every step? ## Term number Position 1, 2, 3, 4, … We often call the position `n`. For 3, 6, 9, 12: the n-th term looks like `3n` (n=1 → 3, n=2 → 6, …) > Patterns are algebra’s playground. The letter n is just “which place in the line”. ## Two questions, every sequence 1. What happens from term to term? 2. Does that exact thing happen on **every** jump shown? If yes, you have a rule. If no, try a different idea (maybe multiply, maybe subtract). ### Term number The first term is position `n = 1`, not n = 0, unless a question says otherwise at this level. For 3, 6, 9, 12 the n-th term is `3n` because seat 1 holds 3, seat 2 holds 6, … ### Patterns are algebra The letter n is just “which place”. That is the same mystery-box idea as x, used for position.

By the end of this lesson

Find the next term of a simple sequence and say the rule in words (add the same number, or multiply by the same number).

Remember

  • A sequence is a list with a rule.
  • Ask: what do I do to get from one term to the next? Does it work every jump?
  • 3, 6, 9, 12… adds 3 each time. Next is 15.
  • 2, 4, 8, 16… multiplies by 2 each time. Next is 32.
  • n is the position: 1st, 2nd, 3rd…

Worked examples

Cover the answer. Try the steps on paper, then open them.

Example 1 — Add-the-same

3, 6, 9, 12, …

  1. 6 − 3 = 3, 9 − 6 = 3, 12 − 9 = 3
  2. Rule: add 3
  3. Next: 12 + 3 = 15

Answer: 15

Check: Check every jump, not only the first.

Example 2 — Multiply-the-same

2, 4, 8, 16, …

  1. 4/2 = 2, 8/4 = 2, 16/8 = 2
  2. Rule: multiply by 2
  3. Next: 32

Answer: 32

Check: Adding 2 fails at the second jump.

Example 3 — Name n

In 3, 6, 9, 12 the 1st term is 3n with n=1.

  1. n = 1 → 3
  2. n = 2 → 6
  3. n = 4 → 12

Answer: nth term 3n

Check: Position times 3.

Common mistakes

Slip Looking at only the first jump.

Fix The same rule must fit every shown step.

Check 2nd→3rd too.

Slip Next after 2, 4, 8, 16 written as 18 (added 2).

Fix The rule is double, so 32.

Test the rule on 4→8.

Slip Thinking n is always 10.

Fix n is the seat number in the line: 1, 2, 3, …

Plug in the seat you want.

Try on paper first

Write the answer, then tap Reveal. These are not the quiz — they are warm-ups.

1. Next: 5, 10, 15, 20, …

Answer: 25

2. Next: 1, 2, 4, 8, …

Answer: 16

3. Next: 20, 17, 14, 11, …

Answer: 8

4. Rule in words for 4, 8, 12, 16?

Answer: Add 4 each time

Touch practice

8 tap / type

Tap an option or type the answer. Retry any miss. Extra generated questions appear after the set if this topic allows it.

Optional picture lab

After practice

Real world

Tile patterns and cricket overs.

Connect

Loops generate sequences.

⭐ Star quiz

9 questions

Finish the touch practice first if you can. Then answer without peeking. Read every “why”.