Vincent\u2019s meter strip got cut off at 68 centimeters. To measure the length of his screwdriver, he writes \u201c81 cm \u2013 68 cm.\u201d Alicia says it\u2019s easier to move the screwdriver over 2 centimeters. What is Alicia\u2019s subtraction sentence? Explain why she\u2019s correct.<\/p>\n\n\n\n
The correct answer and explanation is:<\/mark><\/strong><\/p>\n\n\n\n Correct Answer:<\/strong> Alicia\u2019s subtraction sentence is 81 cm \u2013 70 cm = 11 cm<\/strong>.<\/p>\n\n\n\n Explanation:<\/strong><\/p>\n\n\n\n Vincent is trying to measure the length of his screwdriver using a meter strip that starts at 68 cm instead of zero. He places one end of the screwdriver at 68 cm and the other end at 81 cm. So, he calculates the screwdriver’s length as:<\/p>\n\n\n\n 81 cm \u2013 68 cm = 13 cm<\/strong><\/p>\n\n\n\n This is a correct way to measure the length when the measurement tool does not start at zero. He subtracts the starting point (68 cm) from the ending point (81 cm) to get the length of the object, which gives him 13 cm.<\/p>\n\n\n\n Alicia, however, suggests an easier way. She says that if Vincent moves the screwdriver so that its left end starts at 70 cm<\/strong> instead of 68 cm, it would be easier to subtract. If the right end then reaches 81 cm<\/strong>, she can write the new subtraction sentence:<\/p>\n\n\n\n 81 cm \u2013 70 cm = 11 cm<\/strong><\/p>\n\n\n\n This new subtraction gives a different result because she has moved the object 2 cm forward. The actual length<\/strong> of the screwdriver has not changed; it is still 13 cm. But Alicia\u2019s method of measuring gives 11 cm because she ignored the extra 2 cm she moved the object. So, her result needs to be corrected by adding back those 2 cm<\/strong>.<\/p>\n\n\n\n This means Alicia\u2019s method simplifies subtraction by rounding the starting number to a more convenient figure (like 70 instead of 68), making the subtraction easier. Then she can just add back the 2 cm she moved it. So her final calculation is:<\/p>\n\n\n\n (81 \u2013 70) + 2 = 11 + 2 = 13 cm<\/strong><\/p>\n\n\n\n This confirms that both Vincent and Alicia arrive at the same screwdriver length of 13 cm. Alicia is correct because her method uses simpler numbers and mental math, while still giving the accurate result when adjusted.<\/p>\n","protected":false},"excerpt":{"rendered":" Vincent\u2019s meter strip got cut off at 68 centimeters. To measure the length of his screwdriver, he writes \u201c81 cm \u2013 68 cm.\u201d Alicia says it\u2019s easier to move the screwdriver over 2 centimeters. What is Alicia\u2019s subtraction sentence? Explain why she\u2019s correct. The correct answer and explanation is: Correct Answer: Alicia\u2019s subtraction sentence is […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-39802","post","type-post","status-publish","format-standard","hentry","category-quiz-questions"],"_links":{"self":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/39802","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/comments?post=39802"}],"version-history":[{"count":1,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/39802\/revisions"}],"predecessor-version":[{"id":39803,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/39802\/revisions\/39803"}],"wp:attachment":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/media?parent=39802"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/categories?post=39802"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/tags?post=39802"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}