In Thinking Skills, a data question gives a small table and asks which statement it supports. Children in Year 3 now sit the OC test in Year 4, on 11–12 May 2027.
Data reasoning means deciding what a table really shows, and what it doesn't. A table of birds counted at lunchtime shows which bird was counted most. It doesn't show which bird lives at school all year, or why the pigeons came.
The hardest questions ask what must be true, even when the table never says it. Here is how two days of packed lunches in a class of 30 force an answer, one step at a time.
What the table says
What it forces
22 of the 30 children brought lunch on Thursday
30 − 22 = 8 did not
14 brought lunch on Wednesday
At most 8 of them can be Thursday's non-lunch children
So
At least 14 − 8 = 6 brought lunch on both days
How do data questions show up in the OC Thinking Skills test?
Your child reads a short table, sometimes with a rule such as who gets a ribbon, then picks the statement the data supports or the one that must be true. The Department says Thinking Skills checks critical thinking and problem solving, with no previous knowledge needed, and the section has a range of question types, shown in the practice tests.
The OC Thinking Skills test
What it means for data questions
30 questions in 30 minutes
Read the title and the rule before the numbers
4 options each
Check every option against the table, one by one
No calculator
The sums are small; work them on paper
There are no marks lost for incorrect answers
Cross out what the table doesn't show, then choose
The Department doesn't publish a fixed list of question types. Data reasoning is how our lessons group these questions.
Four steps. Your child treats each statement as a claim to be checked, and says can't tell when the table doesn't decide it.
Read the table first
What does each row and column count? Is there a rule, such as more laps at each session?
Check each statement against the numbers
Find the rows it talks about and do the small sum: twice 8 is 16, not 12.
Watch the exact words
More means more, not the same. Every means no exceptions. Must means true in every possible case.
Ask what the table can't tell
Two days with the same number don't have to be the same children. If the table can't decide, it isn't a must.
What do OC data questions look like?
Three questions from easier to harder: a bird count, a running club rule and a must-be-true question about packed lunches.
Each one shows the answer and the working, so read them with your child. The explanation says why each wrong option is wrong: ask your child which one looked right at first, because that's the habit to fix.
Worked explanation 1
The table shows the birds that Class 4B counted in the school playground during one lunchtime.
Bird
Number counted
Magpie
8
Lorikeet
5
Pigeon
12
Kookaburra
3
Which one of these statements is supported by the table?
AA.
Twice as many pigeons as magpies were counted.
BB.
More pigeons were counted than any other bird.
CC.
More lorikeets were counted than magpies.
DD.
Magpies and kookaburras together were more than the pigeons.
Answer: B
Answer: B (More pigeons were counted than any other bird.)
Read each row of the table: magpies 8, lorikeets 5, pigeons 12, kookaburras 3.
The biggest number is 12, for pigeons, so more pigeons were counted than any other bird.
Why the other options are wrong
A: Twice 8 magpies would be 16, but only 12 pigeons were counted.
C: 5 lorikeets is fewer than 8 magpies, not more.
D: Magpies and kookaburras together make 8 + 3 = 11, which is less than the 12 pigeons.
Worked explanation 2
The table shows how many laps of the oval four children ran at running club. A child gets a ribbon if they ran more laps at each session than at the session before.
Name
Monday
Wednesday
Friday
Kirra
6
8
10
Dev
9
8
9
Sofia
5
9
9
Jai
3
9
8
Who gets a ribbon?
AA.
Sofia
BB.
Jai
CC.
Dev
DD.
Kirra
Answer: D
Answer: D (Kirra)
Check each child from Monday to Wednesday, then from Wednesday to Friday.
Kirra: 6 to 8 is more, and 8 to 10 is more. Kirra gets a ribbon.
Dev: 9 to 8 is fewer. No ribbon.
Sofia: 5 to 9 is more, but 9 to 9 is the same, not more. No ribbon.
Jai: 3 to 9 is more, but 9 to 8 is fewer. No ribbon.
Why the other options are wrong
A (Sofia): Sofia ran the same number of laps on Friday as on Wednesday, and the rule needs more laps at each session.
B (Jai): Jai had the biggest jump from Monday to Wednesday, but he ran fewer laps on Friday.
C (Dev): Dev ran the most laps altogether, but he ran fewer laps on Wednesday than on Monday.
Worked explanation 3
There are 30 children in Class 4T. The table shows how many of them brought a packed lunch from home on each day last week.
Day
Children with a packed lunch
Monday
18
Tuesday
22
Wednesday
14
Thursday
22
Friday
27
Which one of these statements must be true?
AA.
Every child in the class brought a packed lunch on at least one day.
BB.
At least 6 children brought a packed lunch on both Wednesday and Thursday.
CC.
The children who brought a packed lunch on Tuesday also brought one on Thursday.
DD.
On every day, more than half of the class brought a packed lunch.
Answer: B
Answer: B (at least 6 children brought a packed lunch on both Wednesday and Thursday)
On Thursday 22 of the 30 children brought a packed lunch, so only 30 − 22 = 8 children did not.
On Wednesday 14 children brought a packed lunch. At most 8 of them can be children who did not bring one on Thursday.
So at least 14 − 8 = 6 children brought a packed lunch on both Wednesday and Thursday.
Why the other options are wrong
A: On Friday 3 children did not bring a packed lunch, and they could be the same 3 children every day, so we cannot be sure.
C: Both days had 22 children, but they do not have to be the same 22 children.
D: On Wednesday only 14 children brought one, which is less than half of 30.
Which data mistakes cost marks?
Most wrong options sound sensible but aren't shown by the table. Each has a quick check your child can run before choosing.
×
Treating the same as more: if a rule says more laps each time, equal laps break it.
×
Choosing the child or row that looks impressive: check the rule on every step, not the biggest jump or the biggest total.
×
Assuming the same people each day: equal numbers don't mean the same children, so only choose what the numbers force.
What's in the What Does the Data Tell Us? lesson?
What Does the Data Tell Us? (lesson preview)
A short preview from the SelectiveReady lesson “What Does the Data Tell Us?”, on data reasoning for the NSW Selective test.
Published:
Read the video transcript
All right, let's bring in our next suspect, conclusion number two. This one is way bolder. It claims studying more causes better scores. Whoa, that's a huge claim, right? But the real question is, does our evidence actually back that up? Nope. This conclusion is way too strong. It falls right into that classic trap we just talked about, confusing correlation with causation. I mean, sure, the two things seem linked, but this chart doesn't prove that studying is the only reason for good scores. What about other stuff? Like how much sleep did they get? Or maybe they were already good at the subject. The chart doesn't say. So we absolutely cannot claim one causes the other.
The preview, with English and Chinese captions, tests a bold claim against a chart: two things happening together don't prove one caused the other. The full app lesson adds reading tables, supported and unsupported statements and common traps. A free account opens one lesson, How and Why Authors Write; the other lessons need a paid plan.
How can my child practise data questions for free?
Start with Practice test 1, which has Thinking Skills at its real length and time. It's one full practice test with results, with a free account. Every answer is explained, and the results by skill show whether your child loses marks on data questions.
After that, the app has drills by section and topic; a free account drills the free test's questions, and a paid plan opens the rest. At home, keep a small table together, such as the weather or steps walked each day, and take turns making statements for the other to check: true, false or can't tell.
