Lesson · Grade 5 · Mathematics
Solving One-Step Equations
- Grade 5
- Mathematics
- 58 s
- British Columbia
- BC5-MA-24
A bar model and the lines of working solve x + 7 = 19: subtracting 7 undoes adding 7, so 7 comes off both sides, which leaves x = 12. The answer is checked with 12 + 7 = 19, and the video ends on the recap: do the opposite operation to both sides.
Concept: One-step equations
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In one sentence
The question this lesson answers
Let us solve the equation x plus 7 equals 19.
The letter x stands for a number we do not know yet.
Transcript
What the lesson says
Let us solve the equation x plus 7 equals 19.
The letter x stands for a number we do not know yet.
In this bar model, x and 7 together make 19.
To solve the equation, we need to get x on its own.
Since 7 is added to x, subtracting 7 will undo it.
Subtract 7 from both sides, so the two sides stay equal.
On the left, adding 7 and then subtracting 7 leaves just x.
On the right, 19 minus 7 is 12.
So x equals 12.
Check it: 12 plus 7 makes 19, so x equals 12 is right.
To solve a one-step equation, do the opposite operation to both sides.
Curriculum
Where this fits
- British Columbia, Grade 5
Mathematics, Patterns and algebra: one-step equations with variablesBC5-MA-24
Previous: From a pattern to a table of valuesNext: Writing a One-Step Equation from a Story
- British Columbia, Grade 6
Mathematics, Patterns and algebra: one-step equations with whole-number coefficients and solutionsBC6-MA-28
- British Columbia, Grade 7
Mathematics, Patterns and algebra: two-step equations with whole-number coefficients, constants, and solutionsBC7-MA-41
Previous: Equations as a balanceNext: Two-step equations on a balance
This lesson is also listed in Grade 6 and Grade 7.
The outcomes and strands follow the British Columbia curriculum.
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