IB Mathematics Internal Assessment
Money is a context every student understands, which is exactly why so many explorations about it end up as a calculator exercise. Here is how to tell a finance topic with room in it from one that has a ceiling, and how to build the first kind.
You do not need to explain what a price is. The numbers are public, the stakes feel real, and a reader can follow your reasoning straight away. That is a genuine advantage for communication and for personal engagement.
The trap is the formula. Finance comes with ready-made ones for interest, loans and returns, and it is very easy to substitute numbers into them and call that an exploration. If the formula gives the answer, the mathematics is not yours. The marks sit in the decisions around the formula: what you assume, what you leave out, and how you check it.
Compound interest applied to three offers. One formula, used three times, with a winner that anyone could have found on a comparison website. Nothing has to be chosen or justified.
Draw a trend line through a graph and extend it. This is curve fitting, and it ignores the real question, which is whether the past tells you anything at all. If your model cannot be tested on data it has not seen, you cannot say it works.
Pull a published index, plot it, and describe it. You are reporting someone else's number and reading off a graph. There is no question that only your mathematics can answer.
A vague aim with an easy conclusion. Without a precise question, you cannot tell what counts as success, and the mathematics wanders. Narrow it until a result could genuinely surprise you.
Take a loan, a pension contribution or a savings goal that matters to someone you know. Build the model step by step, perhaps with a recurrence you set up yourself, then ask what happens if the rate changes during the term or the payments are missed. The interest is in how fragile the answer is.
Insurance, a warranty, a raffle, a loyalty scheme, an in-app purchase. Define the possible outcomes, assign probabilities you can defend, and work out whether the offer favours the buyer or the seller. The weak point to examine is where your probabilities came from.
A stall, a part-time job, a club budget. Choose what to sell, how much to make or when to open, and state the limits on money, time and stock. Show how the best choice moves when one limit changes. Plenty of scope for calculus or linear methods, depending on your course.
The cost of the same basket of items across shops, a ticket price as the date gets nearer, a fuel price week by week. You know how it was gathered and what went wrong, and the messiness gives you something honest to reason about. See the guide on collecting your own data.
Simple against compound growth, fixed against variable rates, one pricing rule against another. Ask when the two approaches agree, when they part company and why. This is analysis, and it gives you a natural reason to choose between methods.
Take "should I save or invest?" as a starting idea. As it stands it is a slogan. To make it an exploration, keep pressing until the mathematics has decisions in it.
None of that needs advanced mathematics. It needs a question you can defend and a willingness to examine your own result.
Reflection and personal engagement come easily here if you record the moments where your expectation and your result disagreed. Those moments are worth more than another table of balances.
Got a money idea and not sure it can score?
Send me the question and what you plan to do with the numbers. I read real submitted explorations every year, and I will tell you honestly whether the mathematics has enough to do, while there is still time to change direction.
Get the IA sorted with meMore like this: all Maths IA guides. Related: modelling in the Maths IA
These pages are free and stay free, but they are general and your IA is not. Send me your research question, or whatever exists so far, and I will tell you in writing whether the topic has a ceiling on it, where the marks are going, and what to change first. That costs nothing and it comes back within 24 hours.
Written by a serving IB Diploma and Career-related Programme Coordinator and Head of Mathematics, who reads internal assessments across every subject group every year. If you then want the whole draft reviewed properly against all five criteria, that is the paid one, and it is refunded if it does not name at least three specific things to fix.
Get a free verdict Full written review, $99
I never write any part of it. Not a sentence, not a calculation, not your data. Under 18: a parent buys this and the thread is with them. I do not work with students at my own school.