Input/output tables – write the rule – up to 100

key notes :

🌟 What is an Input/Output Table?

• An input/output table shows how numbers change.
• A number goes IN (input) and a new number comes OUT (output).
• The change follows a rule.

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🔢 What is a Rule?

A rule tells what we do to the input number.

Examples of rules:

• ➕ Add a number (add 5)
• ➖ Subtract a number (subtract 2)

The same rule is used for all numbers in the table.

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🧠 How to Find the Rule

Look at the input and output numbers carefully.

Ask:

• Did the number get bigger? ➝ Addition
• Did the number get smaller? ➝ Subtraction

Check how much it changed.

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✏️ Example

Input	Output
2	5
4	7
6	9

👉 Rule: Add 3

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🔍 Steps to Solve

1. Look at one pair (input → output).
2. Find the change (difference).
3. Check if the same change works for all.
4. Write the rule.

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🎯 Numbers Up to 100

Use numbers from 0 to 100.

Practice:

• Add within 100 (e.g., +10, +5)
• Subtract within 100 (e.g., −2, −10)

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⚠️ Important Points

Always use the same rule for the whole table.

Check your rule with all numbers.

Write rules clearly:

• “Add 4”
• “Subtract 6”

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🎉 Fun Practice Idea

Make your own table:

• Input: 10, 20, 30
• Rule: Add 5
• Output: 15, 25, 35

Learn with an example

Let’s practice! 🖊️