Balance equations - four or more digits

Learning Objectives Define an equation and a variable in the context of a balanced number sentence. Explain that the equal sign means 'is the same as' or 'is balanced with'. Solve for an unknown variable in an addition equation with numbers of four or more digits. Solve for an unknown variable in a subtraction equation with numbers of four or more digits. Use inverse operations (addition and subtraction) to isolate a variable and keep an equation balanced. Check their solution by substituting the value back into the original equation to confirm it is true. Imagine a giant seesaw with a 1,500-pound bear on one side! 🐻 How could you figure out the weight of a mystery box on the other side to make it perfectly balanced? In this lesson, you will become a ma...

TermDefinitionExample EquationA math sentence stating that two expressions are equal. It must have an equal sign (=).3,500 + 1,200 = 4,700 is an equation. VariableA letter or symbol that stands for an unknown number we need to find.In the equation 2,100 + x = 5,000, the letter 'x' is the variable. Equal Sign (=)A symbol that means 'is the same as' or 'is balanced with'. Both sides of the equal sign must have the exact same value.The value of 6,000 - 2,000 is the same as the value of 4,000. BalanceThe state where both sides of an equation have the same total value, like a perfectly level scale.The equation 1,500 + 500 = 2,000 is balanced because both sides equal 2,000. Inverse OperationsOpposite operations that 'undo' each other. Addition and subtrac...

The Golden Rule of Equations Whatever you do to one side of the equation, you MUST do to the other side. To keep an equation balanced, if you add or subtract a number from one side of the equal sign, you must add or subtract that same number from the other side. Solving Addition Equations If `a + x = b`, then `x = b - a` To find a missing part in an addition problem, you subtract the part you know from the total. Solving Subtraction Equations If `x - a = b`, then `x = b + a` To find the starting amount in a subtraction problem, you add the other two numbers together.