{"id":613,"date":"2026-01-13T10:00:00","date_gmt":"2026-01-13T10:00:00","guid":{"rendered":"https:\/\/www.rightlobemath.com\/blog\/?p=613"},"modified":"2026-01-13T10:00:00","modified_gmt":"2026-01-13T10:00:00","slug":"build-calculation-speed-practicing-the-10-pair-complements","status":"publish","type":"post","link":"https:\/\/sumomath.com\/content\/build-calculation-speed-practicing-the-10-pair-complements\/","title":{"rendered":"Build Calculation Speed Practicing the 10 Pair Complements"},"content":{"rendered":"<div class=\"embed-container\"><iframe loading=\"lazy\" title=\"Practice the 5 Complement Pairs to Build Calculation Speed\" width=\"1170\" height=\"658\" src=\"https:\/\/www.youtube.com\/embed\/RDtYgRFYJtY?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/div>\n<p>The main method of addition and subtraction on the abacus is understanding and using the 5 complement pairs&nbsp;of 10, i.e. pairs of numbers that add to 10. There are only 5 complement pairs&nbsp;in our base 10 numbering system: 9 and 1, 8 and 2, 7 and 3, 6 and 4, and 5 and 5.&nbsp;The faster students can recall the 10 pair complements, the faster they can add and subtract on the soroban. So students should&nbsp;practice recalling all of the 10 pair complements with the goal of reaching instant recall. Here a couple good 10 pair complement&nbsp;activities to practice recalling the pairs as fast as possible.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The main method of addition and subtraction on the abacus is understanding and using the 5 complement pairs&nbsp;of 10, i.e. pairs of numbers that add to 10. There are only 5 complement pairs&nbsp;in our base 10 numbering system: 9 and 1, 8 and 2, 7 and 3, 6 and 4, and 5 and 5.&nbsp;The faster<\/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-613","post","type-post","status-publish","format-standard","hentry"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.4 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Build Calculation Speed Practicing the 10 Pair Complements - sumomath.com<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/sumomath.com\/content\/build-calculation-speed-practicing-the-10-pair-complements\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Build Calculation Speed Practicing the 10 Pair Complements - sumomath.com\" \/>\n<meta property=\"og:description\" content=\"The main method of addition and subtraction on the abacus is understanding and using the 5 complement pairs&nbsp;of 10, i.e. pairs of numbers that add to 10. 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