{"id":331,"date":"2024-01-29T13:31:43","date_gmt":"2024-01-29T21:31:43","guid":{"rendered":"https:\/\/www.rightlobemath.com\/blog\/?p=331"},"modified":"2020-01-29T15:24:33","modified_gmt":"2020-01-29T23:24:33","slug":"abacus-math-program-lesson-4-simple-multidigit-addition-and-subtraction","status":"publish","type":"post","link":"https:\/\/sumomath.com\/content\/abacus-math-program-lesson-4-simple-multidigit-addition-and-subtraction\/","title":{"rendered":"Abacus Math Program – Lesson 4 – Simple Multidigit Addition and Subtraction"},"content":{"rendered":"

With the basic abacus movements learned in the first 3 lessons\u00a0on a single rod, we are now ready to apply our knowledge to more than 1 rod. If you have not looked at the first 3 lessons or are new to abacus math, I suggest you take a look at\u00a0Lesson 1<\/u><\/a>,\u00a0Lesson 2<\/u><\/a>, and\u00a0Lesson 3<\/u><\/a>\u00a0first which will make your progress easier and faster.\u00a0The power of abacus math\u00a0lies in the treatment of problems 1 digit at a time, 1 rod at a time. Reducing arithmetic problems down to single digit operations on the abacus, a fundamental technique of abacus math and the goal of the four arithmetic algorithms,\u00a0increases calculation speed and improves calculation accuracy.\u00a0Since each rod on the abacus\u00a0represents 1 digit of a base 10 number we reduce the required bead movements needed to a single rod.<\/p>\n

As we progress we will learn\u00a0a simple set\u00a0additional bead movements, 6 in all,\u00a0that manage interactions between rods, i.e. borrow and carry,\u00a0and within rods. For now we will restrict our discussion to working with 1 digit at a time,\u00a0a single rod at a time on the abacus. The methods employed in\u00a0lesson 4 can be extended to numbers of any size. So for\u00a0larger numbers we simple treat the numbers one digit at a time from left to right on the abacus. Processing math and arithmetic calculations from left to right which is opposite of how most of us are taught will have the advantage of lining up our calculation method with exactly how we read and say numbers. So abacus math students can immediately begin calculations as numbers are read or heard and do not have to wait until the entire number is known.<\/p>\n

In the examples, numbers within a circle show the order in which the beads should be moved. Numbers at the tip of an arrow show the value of the beads to be moved.<\/p>\n

Example #1:<\/u><\/strong>\u00a0In this example we start by adding the number 15 to the abacus. First add 1 lower bead with the thumb\u00a0on rod A and the upper 5 bead with the index finger on rod B. Next add 4 to 15 by adding 4 lower beads with the thumb on rod B. The interim sum on the abacus is now 19. Next subtract 1 from 19 by moving 1 lower bead with the index finger away from the bar on rod B. The interim sum is now 18. Lastly subtract 17 from 18 by firstly subtracting 1 from 1 on rod A. Next subtract 7 from 8 on rod B by removing the upper 5 bead and 2 lower beads with the index finger on rod B. The final sum is 1.<\/p>\n

\t\t\t\t\t\t\t\t\t\t\"\"\t\t\t\t\t\t\t\t\t\t\t<\/p>\n

Example #2:<\/u><\/strong>\u00a0In this example we start by adding 17\u00a0to the abacus. First add 1 with the thumb on rod A and pinch with the thumb and index finger\u00a0 the upper 5 bead and 2 lower beads on rod B. Next subtract 12 from 17 by first subtracting 1 from 1 on rod A. Then subtract 2 from 7 on rod B by removing 2 lower beads with the index finger. The interim sum is now 5. Add 10 to 5 by adding 1 to 0 on rod A with the thumb. The interim sum is now 15. Lastly, add 4 to 15 by moving 4 lower beads with the thumb on rod B to the bar. The final sum on the abacus is 19.\u00a0<\/p>\n

\t\t\t\t\t\t\t\t\t\t\"\"\t\t\t\t\t\t\t\t\t\t\t<\/p>\n

Example #3:<\/u><\/strong>\u00a0In this example we start by adding 18 to the abacus. First add 1 to rod A by adding 1 lower bead. Then add 8 to rod B by pinching the upper 5 bead with 3 lower beads. Next subtract 6 from 18 on the abacus by first moving the upper 5 bead with the index finger away from the bar on rod B. Then move 1 lower bead with the index finger away from the bar on rod B. The interim sum is now 12. Add 5 to 12 by moving the upper 5 bead with the index finger on rod B to the bar. The interim sum is now 17\u00a0on the abacus. Finally, subtract 15 from 17 on the abacus by first subtracting 1 from 1 on rod A. Then subtract 5 from 7 on rod B by moving the upper 5 bead with the index finger away from the bar. The final sum on the abacus is 2.<\/p>\n

\t\t\t\t\t\t\t\t\t\t\"\"\t\t\t\t\t\t\t\t\t\t\t<\/p>\n

Next up Lesson 5, 10 Pair Complement Addition<\/u><\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"

With the basic abacus movements learned in the first 3 lessons\u00a0on a single rod, we are now ready to apply our knowledge to more than 1 rod. If you have not looked at the first 3 lessons or are new to abacus math, I suggest you take a look at\u00a0Lesson 1,\u00a0Lesson 2, and\u00a0Lesson 3\u00a0first which<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-331","post","type-post","status-publish","format-standard","hentry"],"_links":{"self":[{"href":"https:\/\/sumomath.com\/content\/wp-json\/wp\/v2\/posts\/331"}],"collection":[{"href":"https:\/\/sumomath.com\/content\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sumomath.com\/content\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sumomath.com\/content\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/sumomath.com\/content\/wp-json\/wp\/v2\/comments?post=331"}],"version-history":[{"count":0,"href":"https:\/\/sumomath.com\/content\/wp-json\/wp\/v2\/posts\/331\/revisions"}],"wp:attachment":[{"href":"https:\/\/sumomath.com\/content\/wp-json\/wp\/v2\/media?parent=331"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sumomath.com\/content\/wp-json\/wp\/v2\/categories?post=331"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sumomath.com\/content\/wp-json\/wp\/v2\/tags?post=331"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}