This problem provides an opportunity to increase familiarity with negative and positive numbers on a number line. The vertical number line is presented as black markings every one meter all the way up a lighthouse and on the underwater support going down to the sea bed, with sea level being "0". In answering the nine questions, children begin to calculate with negative numbers in the context of the distances between the sea creatures. The Teachers' Notes page offers suggestions for implementation, discussion questions, ideas for extension and support, and a link to a related resource, Swimming Pool (cataloged separately).


  • Mathematics > General
  • Education > General

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Grade 3,Make use of structure,NSDL,Grade 4,Grade 5,Visual representation,Number concepts,Mathematics,Social Sciences,Arithmetic,Analyze and persevere,Concept formation,Process skills,Number and operations,Upper Elementary,Mathematical language,Informal Education,Integers,NSDL_SetSpec_ncs-NSDL-COLLECTION-000-003-112-027,Comparison of numbers,Practice Standards,Education,Reason quantitatively,Mental calculation,oai:nsdl.org:2200/20140728160555354T,Communication,Connections,Engineering,Elementary School,Counting,Representation



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