· New Zealand · 5 min read
Reading data, tables and graphs for the NZ numeracy test
Data, tables, and graphs are a significant part of the LNAAT numeracy requirement — and they're one of the strands where people make the most avoidable errors.
The strand that rewards reading, not just calculating
Data, tables, and graphs are a significant part of the LNAAT numeracy requirement — and they’re one of the strands where people make the most avoidable errors. Not because the maths is difficult, but because they rush the reading.
Every data question gives you the information you need to answer it. The skill being tested isn’t just arithmetic — it’s whether you can extract the right information, interpret it accurately, and answer precisely what’s being asked. That’s a skill you can absolutely build with the right kind of practice.
Tables: read the headers before the numbers
Tables are dense. They pack a lot of data into a small space, and it’s easy to pull the wrong number if you’re moving fast. Before you do any calculation:
- Read the title — it tells you what the whole table is about
- Read every column and row header — understand what each dimension represents
- Check the units (is that column in thousands? in NZ dollars? per week?)
- Only then locate the specific cell the question is asking about
A common mistake is reading across the wrong row or down the wrong column because the headers weren’t checked first. Slowing down at the start of a table question saves you from that error.
Bar charts: scale and intervals matter
Bar charts feel familiar — most people are comfortable with them. But test questions often use scales that aren’t numbered in ones. You might see a y-axis going up in 50s, or 250s, or even 2,500s. If the bar lands between two marked intervals, you need to estimate accurately.
- Work out what each division on the scale represents before reading any values
- For questions asking “how much more than” or “how much less than,” calculate the difference between bars — don’t just guess visually
- Watch for bars that look similar in height but represent meaningfully different values at scale
Pie charts: proportions, not exact numbers
Pie charts show parts of a whole — they’re inherently about fractions and percentages. Questions will often ask you to:
- Identify the fraction or percentage represented by a segment
- Calculate an actual value (e.g. if the whole is 400 students and the “science” segment is 25%, how many is that?)
- Compare two segments (which is larger? by how much?)
The calculation is usually straightforward once you’ve correctly read the percentage from the chart. The risk is misreading an unlabelled segment — count the segments first, use the labelled ones to anchor your reading, then estimate unlabelled ones.
Line graphs: trend and change over time
Line graphs typically show how something changes across time — enrolment numbers, test scores, temperature. Questions often ask about:
- The value at a specific point in time
- The overall trend (is it increasing, decreasing, or mixed?)
- The period of greatest change (steepest rise or fall)
- Comparing two data series on the same graph
For trend questions, pay attention to the slope of the line, not just the values. A steep section means a large change over a short time; a flat section means little change. Read these by looking at the shape of the line before hunting for specific numbers.
Averages: mean, median, mode, and range
Data questions often ask you to calculate a summary statistic from a set of numbers. These appear regularly in the LNAAT:
- Mean: add all the values, divide by how many there are
- Median: the middle value when the data is sorted in order — for an even number of values, average the two middle ones
- Mode: the value that appears most often
- Range: the difference between the highest and lowest values
A common slip with the median: forgetting to sort the data first. Always order the values before finding the middle.
Interactive items: data in a new format
The LNAAT includes interactive question types — you might be asked to click on a point on a graph, identify a value on a scale, or match data across a diagram. The underlying skill is the same as a written question, but the input method is different.
If you haven’t encountered these before, they can feel unfamiliar on test day. Practising with this format — even once or twice — removes that surprise factor entirely.
The two-step habit that catches most errors
For any data or graph question, build in two steps before you start calculating:
- Read the question last. Read the chart or table first — understand what it’s showing — then read the question. That way you’re not hunting for something you don’t understand yet.
- Sense-check your answer. Does it seem like a reasonable value given the data? If you’ve calculated that 95% of students chose science in a table where every segment looks roughly equal, something’s gone wrong.
Build your confidence with practice
Data and graphs are one of the most learnable strands in the LNAAT — accuracy comes quickly with the right practice. The free SN Academy diagnostic for NZ applicants includes data questions so you can see exactly where you stand before you begin your full preparation.
— The people of SN Academy
