Math Mammoth Subtraction 1

<p><em>Math Mammoth Subtraction 1</em> is a worktext that covers the <strong>concept of subtraction the relationship between addition and subtraction and the various meanings of subtraction</strong>.</p><p><br></p><p>In the first lesson <em>Subtraction Is Taking Away</em> the child learns the basic meaning of subtraction as taking away objects and learns to write subtractions from an illustration where some objects are crossed out.</p><p><br></p><p>In the next lesson the child counts down to subtract which ties in subtraction with the number line. This is a transitional strategy to solve subtraction problems because later students will learn more efficient ways to subtract but it is important conceptually.</p><p><br></p><p>The following lesson <em>Subtraction and Addition in the Same Picture</em> begins the study of the <strong>relationship between addition and subtraction</strong>. This concept will span several lessons. This first lesson presents two sets of objects such as blue and white balls and the student writes both an addition sentence and a subtraction sentence from this illustration.</p><p><br></p><p>The lesson <em>When Can You Subtract?</em> concentrates on the idea that some subtractions such as 4 ? 5 are meaningless when you think of taking away. The child also makes subtraction patterns in this lesson.</p><p><br></p><p>Then we continue studying the connection between addition and subtraction in the lesson <em>Two Subtractions from One Addition</em>. As an example the child writes both 8 ? 3 = 5 and 8 ? 5 = 3 from the addition 3 + 5 = 8. This idea ties in with fact families a concept that is coming up soon.</p><p><br></p><p>In the lesson <em>Two Parts - One Total</em> we study <strong>word problems</strong> that do not involve the idea of taking away but have two parts making up a total. For example if there are 10 flowers of which some are white and some are red and seven of them are white how many are red?</p><p><br></p><p>Then we study <strong>fact families</strong> which means writing two additions and two subtractions using the same three numbers.</p><p><br></p><p>In the lesson <em>How Many More?</em> students find how many more or how many fewer objects one person has than the other by drawing the objects. This lesson can easily be done with manipulatives if desired.</p><p><br></p><p>In the very next lesson <em>How Many More Problems and Differences</em> we continue the theme this time writing a missing addend addition for problems that ask how many more. For example Veronica has 4 marbles and Ann has 6. We write the missing addend sentence 4 + ___ = 6 to find how many more Ann has. In the next lesson the child then learns to write subtraction sentences for such problems.</p>