MYP Maths: Sequences & Patterns FAQ

MYP 1-3 students need to identify arithmetic and geometric patterns, describe the rule in words, then generalise it using algebraic notation (like $u_n=3n+2$). You'll work with number sequences, shape patterns, and tables, moving from a specific case to a general rule that works for any term.

An arithmetic sequence adds or subtracts the same number each time (a common difference), like 3, 7, 11, 15. A geometric sequence multiplies or divides by the same number each time (a common ratio), like 3, 6, 12, 24. Spotting which type you've got is the first step to finding the rule.

Find the common difference between terms — that's your coefficient of n. Then work out what you'd need to add or subtract to match the first term. For 5, 8, 11, 14, the common difference is 3, so the rule starts $3n$; testing n=1 gives 3, but you need 5, so add 2: $u_n=3n+2$.

If the first differences between terms aren't constant, check the second differences — the differences of the differences. If those are constant, the pattern is quadratic, and the coefficient of $n^2$ is half that constant second difference. This usually appears in MYP 3 with growing shape patterns.

Because the whole point of algebra is generalising — a rule like $u_n=4n-1$ works for the 5th term or the 500th term without you counting every step. According to the IB's MYP: From Principles into Practice guide, this generalisation from specific to abstract is central to developing mathematical reasoning across MYP 1-5.

Most students can spot a pattern but struggle to write it as a general algebraic rule — that jump from 'add 3 each time' to $u_n=3n+c$ is the real hurdle. In my experience teaching MYP 2 and 3, the sticking point is almost always finding the correct constant, not the coefficient.

Under Criterion B (Investigating Patterns), students lose marks for stating a rule without justifying it, or for not testing whether the rule holds for a further case beyond the given data. A correct formula with no reasoning shown typically caps you in the lower achievement bands, even at MYP 3.

Practice with varied pattern types — not just adding sequences, but shape-based ones (matchstick patterns, tile arrangements) — builds the pattern-recognition speed examiners expect by MYP 3. Short, regular practice (10-15 minutes, a few times a week) beats one long session before a test.

Both. MYP mathematics assessment is criterion-based across four criteria — A (Knowing and Understanding), B (Investigating Patterns), C (Communicating), and D (Applying Mathematics in Real-Life Contexts) — and sequences tasks appear in class tests, investigations, and end-of-unit summative tasks, not a single external exam at this stage.

MYP sequence work is the direct foundation for DP Mathematics: Analysis and Approaches, where arithmetic and geometric sequences return formally with sum formulas ($S_n$) and, at HL, links to the binomial theorem. Students who master nth-term reasoning in MYP 3 find the DP AA sequences topic far less of a jump.

MYP sequences focus on spotting patterns and writing a basic nth-term rule, mostly linear and simple geometric cases. DP sequences (Analysis and Approaches Topic 1) add formal sum formulas, sigma notation, and compound interest applications at SL, plus proof by induction links at HL — a genuine step up in rigour, not just harder numbers.

Look for resources built specifically for the MYP criteria — Criterion B investigation-style questions, not just generic algebra drills, since that's what schools actually assess. On RevisionPrep, the MYP mathematics Revision Notes and Topical Worksheets are structured around exactly this: pattern generalisation practice with worked solutions, not just answer keys.