Solving one-step subtraction equations involves finding an unknown whole number in forms such as or , using the relationship between subtraction and addition and interpreting equality as a balance between two quantities. The reasoning is supported by number lines, bar models, and related fact families, and includes checking a solution in the original equation rather than treating subtraction as commutative. The focus is on whole numbers within 1,000; negative numbers, fractions, decimals, and multi-step or more general algebraic equations are not included.
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Detailed Explanation: Solve one-step subtraction equations
An equation is like a balanced scale: both sides have the same value.
When the unknown is being subtracted, as in
read it as: “23 take away a number leaves 8.”
Find the missing part by using addition:
Ask, “What number added to 8 makes 23?” The distance from 8 to 23 is 15, so
Check the answer in the original equation:
The equation is true, so the solution is
Remember: subtraction is not commutative. In this problem, do not switch to . Think about the missing part: the number taken away from 23.
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Linear Equation - Solve for Box, Two Terms, Add and Subtract
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Print this free 'Solve one-step subtraction equations' worksheet to practice this skill away from the computer. Click 'Modify' to easily customize this worksheet to your exact needs.
This Worksheet Includes:
- Linear Equation - Solve for Box, Two Terms, Add and Subtract
- Linear Equation - One Variable, Two Terms, Simple Display
- One-Step Equation - Addition/Subtraction - Solve
- Subtraction - Missing Value, 3 Digit, 1 Number
- Subtraction - Missing Value, 2 Digit, 1 Number
- Linear Equation - Solve for Box, Two Terms, Simple Display
- Linear Equation - Solve for Box, Two Terms
- One-Step Equation - Addition - Solve
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