{"id":1074,"date":"2015-11-09T07:16:09","date_gmt":"2015-11-09T07:16:09","guid":{"rendered":"http:\/\/race4job.com\/blog\/?p=1074"},"modified":"2015-11-09T07:16:09","modified_gmt":"2015-11-09T07:16:09","slug":"maths-tricks-and-shortcuts-7","status":"publish","type":"post","link":"https:\/\/www.race4job.com\/blog\/maths-tricks-and-shortcuts-7\/","title":{"rendered":"Maths Tricks and Shortcuts"},"content":{"rendered":"

MULTIPLYING BY 2\u00bd<\/strong><\/p>\n

Rule: Starting from the first digit of the given number, double each digit and add one-half the given digit. Ignore any fractions. Add any tens digits to the previous answer digit. Add 5 if the preceding digit of the given number is odd. Affix \u00bdto the answer if the given number is odd.<\/p>\n

Use this short cut when the given number is an integer or a decimal number. Mixed numbers and fractions are difficult to handle with this method.<\/p>\n

This short cut will be used in the example:<\/p>\n

517,849 x 2\u00bd<\/p>\n

Double the 5 and add one-half of itself to obtain the first answer digit.<\/p>\n

5 + 5 = 10; \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010 + \u00bd (5) = 10 + 2 = 12<\/p>\n

(The fraction i is ignored.)<\/p>\n

Record 12 as the first two answer digits. Double 1. One-half of 1 is \u00bd, which is Ignored. But since the preceding given digit is odd, add 5 to the result of this step.<\/p>\n

1 + 1 = 2;\u00a0\u00a0\u00a0\u00a0 \u00a02 + \u00bd (1) = 2 + 0 = 2 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a02 + 5 = 7<\/p>\n

Record the 7 as the next answer digit.<\/p>\n

127<\/p>\n

The next given digit is 7.<\/p>\n

7 + 7= 14; \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a014 + \u00bd (7) = 14 + 3 = 17<\/p>\n

The previous given digit, 1, is odd; therefore add 5.<\/p>\n

17 + 5 = 22<\/p>\n

Record the units digit, 2, as an answer digit. Carry the tens digit, also 2, and add it to the previous answer digit. The answer thus far is<\/p>\n

1292 Continue this process with the balance of the given digits.<\/p>\n

8 + 8 – 16; \u00a0\u00a0\u00a0\u00a0\u00a0\u00a016 + 4 = 20;\u00a0\u00a0\u00a0 \u00a020 + 5 = 25<\/p>\n

Record 5; add the 2 to the previous answer digit. The answer at this point is<\/p>\n

12945<\/p>\n","protected":false},"excerpt":{"rendered":"

MULTIPLYING BY 2\u00bd Rule: Starting from the first digit of the given number, double each digit and add one-half the given digit. Ignore any fractions. Add any tens digits to the previous answer digit. Add 5 if the preceding digit of the given number is odd. Affix \u00bdto the answer if the given number is […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1074","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/www.race4job.com\/blog\/wp-json\/wp\/v2\/posts\/1074","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.race4job.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.race4job.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.race4job.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.race4job.com\/blog\/wp-json\/wp\/v2\/comments?post=1074"}],"version-history":[{"count":1,"href":"https:\/\/www.race4job.com\/blog\/wp-json\/wp\/v2\/posts\/1074\/revisions"}],"predecessor-version":[{"id":1075,"href":"https:\/\/www.race4job.com\/blog\/wp-json\/wp\/v2\/posts\/1074\/revisions\/1075"}],"wp:attachment":[{"href":"https:\/\/www.race4job.com\/blog\/wp-json\/wp\/v2\/media?parent=1074"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.race4job.com\/blog\/wp-json\/wp\/v2\/categories?post=1074"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.race4job.com\/blog\/wp-json\/wp\/v2\/tags?post=1074"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}