math · 26 minutes · Official OETT Aligned
Tables & Graphs
Check labels before reading numbers
What to know
- rows and columns
- axis: a line showing a graph scale
- legend: the key to lines or colors
- values between numbered marks
A wrong row, line, or scale can lead to a wrong answer even when your math is right.
The core rule
Read the title, units, scale, and key. Then find the value the question asks for.
In a table, match the correct row and column. On a graph, use the key to find the right line or bar. Check the gap between numbered marks. On an evenly spaced scale, a point halfway between 20 and 30 is 25.
Worked examples
Example 1: easy
Tuesday's 18 loads exceed Monday's 12 by 6.
- Read the Monday row as 12 loads and Tuesday as 18 loads.
- Subtract the same-unit values: 18 − 12 = 6 loads.
Compare the correct days using the same units.
Example 2: medium
A midpoint between 20 and 30 on an even scale represents 25.
- The labeled span from 20 to 30 is 10 units.
- The midpoint divides the span into two equal 5-unit intervals: 20 + 5 = 25.
Halfway between 20 and 30 is 25 on an even scale.
Example 3: hard
A two-series graph requires matching the legend before comparing the same month.
- Use the legend to identify the two lines before choosing a month.
- At that one month, read both values from the same position on the graph and subtract them.
- Reject comparisons that mix a month from line A with a different month from line B.
Compare the two lines at the same month.
Common mistakes
Use whichever printed number is nearest the point.
Follow the correct line or row and use the spacing between marks to read the value.
Put it into practice
Use guided explanations, check your answers, and try a new variation.