Kentucky Down Under - Olssen

Invented Strategies - The "Matthew" Plan

On the first day of teaching subtraction with regrouping, one student began explaining his own way of solving problems so that he didn't have to regroup - he could use mental strategies instead.  I listened intently as he showed us how he worked through a problem.  At first, I thought it was a fluke!  Then, I realized this strategy would work well with almost any subtraction problem.  The students have loved Matthew's method!  In Matthew's strategy, he makes the initial problem easier to solve by forcing his first answer to be a "nice" number.  From there, he uses several different strategies including counting up, counting down, and mental math.  This plan works best with 2 and 3 digit numbers because the subtraction becomes difficult with more complex numbers.

Subtraction Strategies - Modeling the Process

This video shows the "Modeling" method for solving subtraction problems.  This strategy is great for students who are moving from concrete learning (using manipulatives) to more abstact learning.  In this method, students draw pictures to represent the highest number, then begin taking away the smaller number.  Children can "see" the steps of traditional regrouping.  This helps build number sense because students are visualizing the base ten representation of numbers.  This is not the most effecient means to solve a subtraction problem, but it effective.  One word of caution - your child does not have a "picture" to use for numbers larger than 4 digits. 

Invented Strategies - Partial Differences

In this method, students use the expanded form of numbers to create simpler subtraction problems and avoid regrouping.  One of the most common problems students face in solving problems is that they want to begin on the left and work to the right.  In the traditional regrouping method, this is not possible and leads to errors.  In the partial difference method, students can work left to right, leading to fewer errors.  The students have enjoyed this method because of the exposure to negative numbers.  If an answer is a negative number, the student puts a minus sign in front of it.  If the answer is a positive number, the student puts a plus sign in front.  Students must be flexible in their thinking and be able to do mental computations.

Empty Number Line Strategy

The empty number line strategy helps students visualize the "counting back" nature of subtraction.  This strategy allows students to break the problem down into more manageable steps and to solve easier problems.  This method can take up a LOT of space!  Students continue to improve their number sense by utilizing this strategy.  It also allows students to solve from left to right.

Subtraction Practice

Here are a few websites to use to practice your subtraction skills.

Speed game – name the fact: http://www.oswego.org/ocsd-web/games/SpeedGrid/Subtraction/urikasub1res.html

Subtraction: http://www.amblesideprimary.com/ambleweb/mentalmaths/subtractiontest.html
Subtraction with and without regrouping: http://www.oswego.org/ocsd-web/games/Ghostblasters3/ghostsub3.html

Vertical 2 digit – 2 digit: http://www.slidermath.com/wjava/Subtv2.shtml

Addition Practice

Here are a few websites you can use to practice your addition skills.

http://www.bbc.co.uk/schools/ks2bitesize/maths/number/addition/play.shtml - practice facts to 100

http://www.amblesideprimary.com/ambleweb/mentalmaths/pyramid.html - fact practice

http://www.funbrain.com/cgi-bin/fract.cgi?A1=s&A2=3&A15=0 - 2 digit + 2 digit

http://www.funbrain.com/cgi-bin/fract.cgi?A1=s&A2=3&A15=0 - 3 digit + 3 digit

Paper Bag Characters Project

Paper Bag Characters


Character: _______________________________

For this assignment, you will need to choose a character from your text. Be sure to choose a rich, memorable character – it will make it easier to complete your assignment. You will need a paper bag to complete this assignment.

This assignment has several components:

o On the front panel of your paper bag, draw a picture of your character. You may wish to draw the picture on another piece of paper and then glue it onto the bag.

o On one of the side panels, write about your character’s likes and dislikes. Include a bulleted list for each and use supporting evidence from the text.

o On the other side panel, write about how other characters in the text react and interact with your character. Again, don’t forget to use supporting evidence from the text.

o On the back panel, explain how your character changed throughout the text. What was your character like at the beginning of the text? At the end? Why did your character change? Include supporting evidence from the text.

o Inside your bag, include at least 3 items that you would associate with your character. Be prepared to explain and defend your choices in the oral presentation.

o Oral Presentation – You will be asked to orally present your assignment. In your assignment, explain who your character is and what text he or she is from. Briefly explain your information on the two side panels and back panel (DO NOT READ your information – just give us a quick summary.) Show us the items you put in your bag. Explain why you chose these items and why they are important to your character. You may DRESS as your character for this presentation.

o ASSIGNMENT DUE DATE: October 31, 2012!!!!

Friday MATH QUIZ

The blue group and green group students will have a QUIZ on Friday, August 31.  This quiz will cover reading and writing numbers in standard form, word form, and expanded form.  Students will also be asked to recognize numbers using base ten blocks.  The red group will take the same quiz on Tuesday, September 4.  There is a link to Funbrain on the right hand side of this page that will allow your child to practice standard and word form.