Equations: one-step adding and subtracting

Author: Jess Prior

This type of activity is known as Practice. Please read the guidance notes here, where you will find useful information for running these types of activities with your students.

I love this sequences of questions that Jess has created. Here are a few reasons why:

  • Early on students are presented with questions where the variable is on the right-hand side of the equals sign, or where the variable comes second in the expression. When I have taught solving linear equations in the past, all my early examples looked the same. My students could solve them, but they also started to believe that was what equations looked like, and hence it should have been no surprise to me when they freaked out some time in the future when they came across an equation that looked different. Here, students are confronted with those differences early on so they have an opportunity to get comfortable
  • I love the use of equations that are equal to 0. Thinking back, very rarely have I given my students linear equations that equal zero. In fact, I think the first time many of my students encountered an equation equal to 0 was when we did quadratics. With zero being such a key concept in equations, graphs, and indeed the whole of algebra, I really like that it is tackled early on in this sequence of equations
  • I really like the introduction of fractions and negative numbers into this sequence, this tapping into the benefits of interleaving. There would be potential for the teacher – or better still, the students – to extend this sequence to incorporate decimals and other areas of maths
  • But the main thing I love about this sequence of questions is how it shows students the benefit of solving equations using the balance method. Now, in the past I have started off a unit of teaching on solving linear equations by explaining to students how the balance method works, and telling them why it is so important. But no-one in their right mind would solve an equation like 3 + x = 8 using the balance method. We – teachers and students alike – can just see it is 5, and to slow students down and force them to work out the answer in a less efficient way will be frustrating for all invovled. So now, when using this set of questions, I tend to let students go ahead and solve the equations how they want. And what I have found is that as they progress through the sequence, it becomes more and more difficult to just “see” the answer. Hence, this sequence creates a need for a better technique to solve equations. I hope that makes sense!

1. Example-Problem Pair

2. Intelligent Practice

 

3. Answers

 

4. Downloadable version

 

5. Alternative versions

  • feel free to create and share an alternate version that worked well for your class following the guidance here