Knowing Numbers; Making Connections

Over the past 3 years, all the MV Elementary staff have been learning new strategies/techniques for Math in the classroom.  The CGI (Cognitive Guided Instruction) training has taken place over classes in the summer and during Professional Development days.  With each lesson and day the ideas become easier for both teacher and student. 

One of the ways we work on number work is with True/False sentences.  Sometimes the students must figure out if a number sentence is true or false and sometime students need to figure out how to make the number sentence true (and explain how they came to the solution they did).  For example:  7+2=2+7.  One student explained her answer of "T" by saying 7 apples plus 2 apples is the same total as 2 apples plus 7 apples.  Once we have established that addends can be switched and get the same total, we introduce the vocabulary of the "commutative property".  Another example is:  8+3= ___ +2.  Usually students find the sum for the known numbers and then decide what would be needed to make the other side of the equation true.  A few students will use relationships between numbers to solve.  Such as, "I know 2 is one less than 3, so the ___ should be 1 more than 8."  When we are trying to build connections between known numbers/equations and unknown numbers we refer to it as relational thinking. 

Rounding is another important skill we use.  We also refer to it as estimating.  Currently we are working on rounding with hundreds and tens.  A saying in our classroom to help us with the task is "5 or above, give it a shove."  For example, in the number 27, when rounding to the tens, we use the ones to help us decide.  The ones column in a 7, that is above 5 so we "shove" the tens column up to 30.  The second part of the saying is "4 or less, don't mess", meaning if the ones column is 4 or less, don't mess with the tens column (22 would round to 20, not up to 30).  In addition to the saying, we also practice with the number line and ways to make groups of 10 to aid students in rounding.  One way to practice with your child w/o making it seem like homework is to talk about rounding when dealing with money.  At my house we use grocery shopping as a great way to talk about estimating.  So if a package of doughnuts costs $3.98, would I round my number to 3.00 or 4.00?  As a class we discuss how rounding/estimating helps us with number work b/c numbers with zeros are "friendly" to manipulate.

Finally, I am including 2 websites that will continue to help students with basic fact fluency (building speed and accuracy with numbers) and also problem solving/strategies.  They are http://www.aleks.com/ (students have usernames and passwords already) and http://www.coolmath-games.com/. 
Good luck and have fun!
Mrs. C.