Strategies for Multi-Digit Subtraction: Understanding Methods, Thesis of Business Accounting

Download Strategies for Multi-Digit Subtraction: Understanding Methods and more Thesis Business Accounting in PDF only on Docsity! MATH 6562 Multi Digit Subtraction Methods Master of Science in Education, Walden University MATH 6562: The Base Ten Number System and Operations: Addition and Subtraction Multi Digit Subtraction Methods Regrouping is not an easy strategy and can confuse students if they do not have a concrete understanding of the strategy. Regrouping within 100 is a strategy that is taught at the second-grade level. If taught earlier, it could become even more confusing and errors could be made that students do not understand how to correct (Fuson, Clements, & Beckmann, 2011). Having a concrete understanding of strategies that can be used to solve multi digit subtraction problems will help students to arrive at the correct solution. There are many strategies that students can use to solve a multi digit subtraction problem. Just like with addition, students must have concrete knowledge of place value. Place value drawings will allow the student to draw a representation for each place value. This is similar to using sticks and dots to represent numbers. The strategy of adding up to find the unknown addend involves counting on and making tens. Traditional expanded notation breaks apart the numbers into hundreds, tens, and ones in order to solve. The strategy of alternating current common methods requires ungrouping before subtracting. Ungrouping where needed ungroups the place value that needs it first, and not ungrouping where it is not needed (Fuson & Zaritsky, 2005). Using each of the above-described methods, I calculated the problem 323-159. The solutions for this problem, using all of the multi digit subtraction methods, are shown in the appendix. There are a few of these methods that were used with ease, while others required additional support. The most common of these methods is the place value drawing. This strategy has been used for years and was the method that I was taught to solve with many years ago. The most difficult method was the alternating current common. While the solution made sense, it was the hardest for me because it was not a strategy that I am familiar with. With this strategy, all of the regrouping that is needed is done in the beginning. While tough, I feel it is a great method to use and teach because it reduces the chance of errors. This would be a great method for students that may be having a problem understanding place value. “Methods that alternate processes are much more difficult than methods in which you can do all of one process and then do all of the other process” (Fuson, Clements, & Beckmann, 2011, p.75). There are many similarities within all of these strategies. Not only do they all require some sort of regrouping, but they must also all be lined up in the correct place value order. Subtracting is done column by column and regrouping is used as needed so that you do not end up with a negative solution (Beckmann, 2018). Unlike the addition strategies, with the subtraction methods, you are able to start at the right or left and still arrive at the correct solution. Just like there are similarities, there are also differences. Within the 5 subtraction methods, the adding up method is the only one that you use adding up to figure out what is missing. In traditional ungrouping, the ungrouping is done as you solve the problem. With ungrouping first when needed, all ungrouping must be done first. As expected, there will be some misconceptions. The common misconception with place value drawings id that students must accurately represent when/if they borrow from a column so that they are able to accurately adjust that number in the problem. With adding up to find an unknown addend, students must understand to switch from subtraction to addition in order to solve. If students are not able to make that switch, this will be a hare strategy for them. The expanded notation strategy can be difficult for students that do not have a concrete understanding of writing expanded notation. They have to know that expanded notation is written as the actual place value, for example, 357 would be written as 300+50+7 (Learn Zillion, n.d.). With the strategy of alternation current common, students must know understand when and how they ¥ | D Couse lame MLA orZtibH 3 B aweiocy | iering Current Commer 323 ooo poA 54 i 4 ieaman 2318 ¥ “ee Dae VL ieee PB Type tere toseaich © mites eo¢ Seem) Mtn Beat -Ononk 3 |B Soneee orm RIAD-ATOT SS 2 bs 1k 1 +e eoca) intext prs vouluse Mage est pono wr ay se é eee €5¢ 6 Bre 9 goca) Type twee toseaich HE) toc 1) -Heeattatincham ¥¢ | op eo - o x step 4 Jake ovo0y 9 ef with comm. dilng isp to Find tintnowon cation) 328-169 isa4+J- 293 1594(3k ivy Aas + aS 154 4 Wok 319 4+ 100 +00: Ilo}