{"id":54,"date":"2023-07-28T14:35:19","date_gmt":"2023-07-28T18:35:19","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/tradeskillsforsuccessnumeracy\/?post_type=chapter&p=54"},"modified":"2023-10-27T15:36:10","modified_gmt":"2023-10-27T19:36:10","slug":"estimation","status":"publish","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/tradeskillsforsuccessnumeracy\/chapter\/estimation\/","title":{"raw":"Estimation","rendered":"Estimation"},"content":{"raw":"Estimation<\/strong><\/span> is a useful tool in mathematical problem-solving. Estimating gives you an approximate or \u201cballpark\u201d answer. It is important to be able to make estimates in your head before you use a calculator, to enable you to double- check your answer in case you press the wrong key on the calculator. People often estimate differently; there is no one correct way to estimate. It takes practice to get good at choosing numbers that make estimating easier.\r\n\r\nHere are some estimating strategies:\r\n

1. Round to numbers that are easy for you to compute.<\/h2>\r\nFor example, about how much is 29 \u00d7 14? Some possible estimates are:\r\n
    \r\n \t
  • 25 \u00d7 16 = 400<\/li>\r\n \t
  • 30 \u00d7 10 = 300<\/li>\r\n \t
  • 30 \u00d7 15 = 450<\/li>\r\n<\/ul>\r\n

    2. Use numbers that make sense to you<\/h2>\r\nWhen you round, sometimes the result will be an underestimate (less than the exact answer), and sometimes it will be an overestimate (more than the exact answer).\r\n\r\nEstimate these problems:\r\n\r\n[latex]\\begin{array}{lll} 31\\times4&30\\times4=120&\\text{a little more than }120 \\\\\r\n48\\times5&50\\times5=250&\\text{a little less than }250\\\\\r\n17\\times21.2&20\\times20=400&\\text{about }400\\end{array}[\/latex]\r\n

    3. Choose numbers that are compatible and easy to work with for the problem.<\/h2>\r\nFor example, how much is 2775 divided by 6? Some possible estimates are:\r\n\r\n3000 \u00f7 6 = 500","rendered":"

    Estimation<\/strong><\/span> is a useful tool in mathematical problem-solving. Estimating gives you an approximate or \u201cballpark\u201d answer. It is important to be able to make estimates in your head before you use a calculator, to enable you to double- check your answer in case you press the wrong key on the calculator. People often estimate differently; there is no one correct way to estimate. It takes practice to get good at choosing numbers that make estimating easier.<\/p>\n

    Here are some estimating strategies:<\/p>\n

    1. Round to numbers that are easy for you to compute.<\/h2>\n

    For example, about how much is 29 \u00d7 14? Some possible estimates are:<\/p>\n

      \n
    • 25 \u00d7 16 = 400<\/li>\n
    • 30 \u00d7 10 = 300<\/li>\n
    • 30 \u00d7 15 = 450<\/li>\n<\/ul>\n

      2. Use numbers that make sense to you<\/h2>\n

      When you round, sometimes the result will be an underestimate (less than the exact answer), and sometimes it will be an overestimate (more than the exact answer).<\/p>\n

      Estimate these problems:<\/p>\n

      [latex]\\begin{array}{lll} 31\\times4&30\\times4=120&\\text{a little more than }120 \\\\ 48\\times5&50\\times5=250&\\text{a little less than }250\\\\ 17\\times21.2&20\\times20=400&\\text{about }400\\end{array}[\/latex]<\/p>\n

      3. Choose numbers that are compatible and easy to work with for the problem.<\/h2>\n

      For example, how much is 2775 divided by 6? Some possible estimates are:<\/p>\n

      3000 \u00f7 6 = 500<\/p>\n","protected":false},"author":2001,"menu_order":3,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-54","chapter","type-chapter","status-publish","hentry"],"part":42,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/tradeskillsforsuccessnumeracy\/wp-json\/pressbooks\/v2\/chapters\/54","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/tradeskillsforsuccessnumeracy\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/tradeskillsforsuccessnumeracy\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/tradeskillsforsuccessnumeracy\/wp-json\/wp\/v2\/users\/2001"}],"version-history":[{"count":6,"href":"https:\/\/pressbooks.bccampus.ca\/tradeskillsforsuccessnumeracy\/wp-json\/pressbooks\/v2\/chapters\/54\/revisions"}],"predecessor-version":[{"id":813,"href":"https:\/\/pressbooks.bccampus.ca\/tradeskillsforsuccessnumeracy\/wp-json\/pressbooks\/v2\/chapters\/54\/revisions\/813"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/tradeskillsforsuccessnumeracy\/wp-json\/pressbooks\/v2\/parts\/42"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/tradeskillsforsuccessnumeracy\/wp-json\/pressbooks\/v2\/chapters\/54\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/tradeskillsforsuccessnumeracy\/wp-json\/wp\/v2\/media?parent=54"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/tradeskillsforsuccessnumeracy\/wp-json\/pressbooks\/v2\/chapter-type?post=54"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/tradeskillsforsuccessnumeracy\/wp-json\/wp\/v2\/contributor?post=54"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/tradeskillsforsuccessnumeracy\/wp-json\/wp\/v2\/license?post=54"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}