A population rises from 40 to 72. How much did it grow, and what can the numbers actually prove?
I can calculate population change and use data to make a careful claim.
- I find the absolute and percent change.
- I cite values from the table.
- I do not claim a cause the data cannot show.
A population is a group of the same species in a defined area. Absolute change tells how many were added or lost. Percent change compares that difference with the starting value. A trend can describe a pattern, but a pattern alone does not establish what caused it.
| Year | Count | Year | Count |
|---|---|---|---|
| 2018 | 40 | 2022 | 60 |
| 2019 | 48 | 2023 | 66 |
| 2020 | 54 | 2024 | 72 |
| 2021 | 51 |
1. From 2018 to 2024, how many more organisms were counted, and what was the percent increase? Show your calculation.
2. Describe one trend using values from the table. Can this table tell you what caused the change? Explain in 2–3 sentences.
Sentence starter: “The population increased by ___, or ___%. The data show ___, but they do not tell us ___.”
Worked example with different years
From 2021 to 2022, the count changes from 51 to 60.
Round at the end. The denominator is 51 because percent change compares the difference with the starting value.
Check your calculation after trying
Absolute change: 72 − 40 = 32. Percent increase: 32 ÷ 40 × 100 = 80%.
A careful claim could say: “The count increased overall from 40 in 2018 to 72 in 2024, with a small dip from 54 to 51 in 2021. The table does not include habitat, food, movement, reproduction, or sampling information, so it cannot identify the cause.”
Optional stretch challenge
Explain why the statement “food shortage caused the 2021 dip” is an inference rather than an observation. Name one kind of evidence you would need to test it.
Complete the challenge in your notebook or your teacher’s assigned response space. Follow your class’s usual commenting and submission directions. For more practice, explore the math pathways and virtual labs.
10 Responses
The population increased by 6 or 8 each year. In 2021 the population decreased by 3.
40 to 72 organisms . That is an increase of 32 organisms . The percent increase was 80% ( 32/40 x 100 ). The population grew each year, except for 2021 when it fell from 54 to 51. The data indicate an overall population increase . But the data do not tell us what caused the change.
The population increased by 32, or 80% the data show a consistent overall increase in the organ from the thing but they do not tell us about it and what’s happening.
The population increased by 6, or 6%. The data shows that from year 2023 to 24 the population increased by 6, but they do not tell us for year 2025 what number the population increased by.
The population increased by 32. The data shows how it increased but they do not tell us how much.
The population increased by __60_, or _51__%. The data show __9_, but they do not tell us _5.7__.
The population increased by 32, or 80% the date shows that the organism population grew from 40 to 72 between 2018 and 2024 with only a temporary drop in 2021 but they do not tell us the specific environmental factors that made all these changed
The data show an overall upward trend from 40 organisms in 2018 to 72 organisms in 2024, despite a small dip down to 51 organisms in 2021. However, this table only provides counts and dates, meaning it cannot tell us why the population changed. The pattern itself does not reveal the underlying causes, such as changes in food supply, predators, or weather conditions.
The population increased by 32 organisms, or 80%. The data show a steady upward trend from 40 organisms in 2018 to 72 organisms in 2024, with only a minor dip to 51 organisms in 2021. However, these figures do not tell us why the changes happened, as a data table only tracks numerical patterns and cannot prove environmental causes like food supply, predators, or disease.
The population increased by 32, or 80%. The data show a steady upward trend from 2018 to 2024, with only a temporary drop to 51 organisms in 2021, but they do not tell us what environmental factors, such as food availability or predators, caused these changes