Subtraction | Mini Lesson
In this 20-minute mini lesson, adult learners practice subtraction using realistic health-related data such as blood pressure changes, medication counts, calorie deficits, and appointment totals. The lesson emphasizes accurate calculation, interpreting results, and communicating simple health information clearly.
| Term | Definition |
|---|---|
| subtract | To take one number away from another to find how much is left or the difference. |
| difference | The answer to a subtraction problem. |
| reduce | To make smaller or lower. |
| total | The amount altogether before subtraction. |
| remaining | What is left after some is taken away. |
Present one simple example, such as 'A person had 12 pills and took 5. How many are left?' Model reading the problem and finding the difference.
Listen, solve mentally or on paper, and share the answer aloud.
Explain that subtraction helps us understand changes in health data. Model 2 examples on the board, such as '150/95 dropped to 138/88' and 'A patient had 18 bottles of water for the week and used 7. How many remain?' Show how to identify the starting number and the amount taken away.
Identify the larger starting number, the amount subtracted, and the answer in each example.
Work through 3 challenging examples with the class: calorie intake reduced by 250, steps left to reach a goal, and medication doses used versus remaining. Ask learners to explain each step and check the answer.
Solve each problem with the teacher, explain reasoning, and compare answers with a partner.
Give 1 or 2 quick subtraction problems related to health and circulate to support. Ask learners to write the subtraction sentence and answer in words.
Complete the problems independently and write the result in a health-related sentence.
Review the key idea: subtraction shows change, decrease, or what remains. Ask one volunteer to explain how subtraction could be used in daily health tracking.
State one thing learned and give one example of subtraction in health.
Subtraction helps us understand how health numbers change over time. Today we used it to find what was left, what was reduced, and how much had changed.