Differences in Swedish and Norwegian pre-service teachers’ explanations of solutions of linear equations

Solving linear equations is a cornerstone in the learning of algebra. There are two main strategies for solving a linear equation, ‘swap sides swap signs’ (SSSS) and ‘do the same to both sides’ (DSBS). While SSSS can often be more efficient for solving equations, DSBS has been shown to better promot...

Full description

Saved in:
Bibliographic Details
Main Authors: Niclas Larson, Kerstin Larsson
Format: Article
Language:Danish
Published: NTNU Open Access Journals 2024-10-01
Series:Nordic Journal of STEM Education
Online Access:https://www.ntnu.no/ojs/index.php/njse/article/view/4074
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850285074097897472
author Niclas Larson
Kerstin Larsson
author_facet Niclas Larson
Kerstin Larsson
author_sort Niclas Larson
collection DOAJ
description Solving linear equations is a cornerstone in the learning of algebra. There are two main strategies for solving a linear equation, ‘swap sides swap signs’ (SSSS) and ‘do the same to both sides’ (DSBS). While SSSS can often be more efficient for solving equations, DSBS has been shown to better promote the learning of algebra. Thus, the preference of SSSS or DSBS might depend on the purpose of solving equations. Since both approaches are common, mathematics teachers, and thus also pre-service teachers (PSTs), must be familiar with both SSSS and DSBS. This study draws on data from 161 Swedish and 146 Norwegian PSTs. They were given a correct but short and unannotated solution to the linear equation x + 5 = 4x − 1. The PSTs were invited to explain the provided solution for a fictive friend. Of the Norwegian PSTs, 2/3 explained the additive steps in the solution by SSSS, while only 1/3 of the Swedish PSTs applied SSSS. Consequently, DSBS was more frequent among the Swedish PSTs regarding the additive steps. However, in the final, multiplicative step, 3/4 of the Norwegian PSTs invoked DSBS. On the contrary, among the Swedish PSTs, the proportion applying DSBS for the multiplicative step decreased, and it was common to provide an incomplete explanation of the final operation. We also analysed how mathematics textbooks for secondary school presented how to solve linear equations. In Sweden, all textbooks utilised DSBS through the whole solution for all years in secondary school. This also applied for Norwegian textbooks for the first two years of lower secondary school. However, in last year of lower secondary school, they changed their approach and promoted an SSSS strategy in additive steps, while DSBS was still suggested for multiplicative steps. This might explain the differences between the two countries regarding the PSTs’ preferences of solution strategies. We suggest that these results can be useful for teacher education, since increased awareness of PSTs’ pre-knowledge is beneficial to support their development of teaching linear equations.
format Article
id doaj-art-528865a1997d4bbfa6852723be8e4011
institution OA Journals
issn 2535-4574
language Danish
publishDate 2024-10-01
publisher NTNU Open Access Journals
record_format Article
series Nordic Journal of STEM Education
spelling doaj-art-528865a1997d4bbfa6852723be8e40112025-08-20T01:47:24ZdanNTNU Open Access JournalsNordic Journal of STEM Education2535-45742024-10-018210.5324/njsteme.v8i2.4074Differences in Swedish and Norwegian pre-service teachers’ explanations of solutions of linear equations Niclas Larson0Kerstin Larsson1University of AgderLuleå University of TechnologySolving linear equations is a cornerstone in the learning of algebra. There are two main strategies for solving a linear equation, ‘swap sides swap signs’ (SSSS) and ‘do the same to both sides’ (DSBS). While SSSS can often be more efficient for solving equations, DSBS has been shown to better promote the learning of algebra. Thus, the preference of SSSS or DSBS might depend on the purpose of solving equations. Since both approaches are common, mathematics teachers, and thus also pre-service teachers (PSTs), must be familiar with both SSSS and DSBS. This study draws on data from 161 Swedish and 146 Norwegian PSTs. They were given a correct but short and unannotated solution to the linear equation x + 5 = 4x − 1. The PSTs were invited to explain the provided solution for a fictive friend. Of the Norwegian PSTs, 2/3 explained the additive steps in the solution by SSSS, while only 1/3 of the Swedish PSTs applied SSSS. Consequently, DSBS was more frequent among the Swedish PSTs regarding the additive steps. However, in the final, multiplicative step, 3/4 of the Norwegian PSTs invoked DSBS. On the contrary, among the Swedish PSTs, the proportion applying DSBS for the multiplicative step decreased, and it was common to provide an incomplete explanation of the final operation. We also analysed how mathematics textbooks for secondary school presented how to solve linear equations. In Sweden, all textbooks utilised DSBS through the whole solution for all years in secondary school. This also applied for Norwegian textbooks for the first two years of lower secondary school. However, in last year of lower secondary school, they changed their approach and promoted an SSSS strategy in additive steps, while DSBS was still suggested for multiplicative steps. This might explain the differences between the two countries regarding the PSTs’ preferences of solution strategies. We suggest that these results can be useful for teacher education, since increased awareness of PSTs’ pre-knowledge is beneficial to support their development of teaching linear equations.https://www.ntnu.no/ojs/index.php/njse/article/view/4074
spellingShingle Niclas Larson
Kerstin Larsson
Differences in Swedish and Norwegian pre-service teachers’ explanations of solutions of linear equations
Nordic Journal of STEM Education
title Differences in Swedish and Norwegian pre-service teachers’ explanations of solutions of linear equations
title_full Differences in Swedish and Norwegian pre-service teachers’ explanations of solutions of linear equations
title_fullStr Differences in Swedish and Norwegian pre-service teachers’ explanations of solutions of linear equations
title_full_unstemmed Differences in Swedish and Norwegian pre-service teachers’ explanations of solutions of linear equations
title_short Differences in Swedish and Norwegian pre-service teachers’ explanations of solutions of linear equations
title_sort differences in swedish and norwegian pre service teachers explanations of solutions of linear equations
url https://www.ntnu.no/ojs/index.php/njse/article/view/4074
work_keys_str_mv AT niclaslarson differencesinswedishandnorwegianpreserviceteachersexplanationsofsolutionsoflinearequations
AT kerstinlarsson differencesinswedishandnorwegianpreserviceteachersexplanationsofsolutionsoflinearequations