Second Grade Parent Math Information Information gathered by 2 nd Grade Teachers (all trained Cognitively Guided Instruction teachers) 1
Your child is learning: Common Core National Math Standards (College and Career Readiness Standards) v 2010 Arizona Math Standards v Kyrene Math Standards http://www.azed.gov/azcommoncore/families/ 2
Times have changed… Today’s students must master advanced skills in mathematics, science, and technology to stay on track for college and for promising careers. Mathematics teaches ways of thinking that are essential to work and civic life. *Students who take algebra and geometry go on to college at much higher rates than those who do not (83% vs. 36%). *Most four-year colleges require three to four years each of high school math and science for admission. *Almost 90% of all new jobs require math skills beyond the high school level 3
Second Grade- Five Domains Operations and Algebraic Thinking Numbers in Base Ten Geometry Measurement and Data Mathematical Practices 4
We teach problem solving to help improve: Mathematical Practices 1. Make sense of problems and persevere in solving them. 2. Reason abstractly and quantitatively. 3. Construct viable arguments and critique the reasoning of others. 4. Model with mathematics. 5. Use appropriate tools strategically. 6. Attend to precision. 7. Look for and make use of structure. 8. Look for and express regularity in repeated reasoning. 5
Your child using mathematical procedures in the classroom… 6
Your child using mathematical procedures in the classroom… 7
Common Addition and Subtraction Situations Your child is Result Unknown Change Unknown Start Unknown Two bunnies sat on the Two bunnies were sitting Some bunnies were sitting grass. on the grass. Some more on the grass. Three more expected to Three more bunnies bunnies hopped there. bunnies hopped there. hopped there. How many Then there were five Then there were five Add to bunnies are on the grass bunnies. How many bunnies. How many know how now? bunnies hopped over to bunnies were on the grass 2 + 3 = ? the first two? before? 2 + ? = 5 ? + 3 = 5 to solve 12 Five apples were on the Five apples were on the Some apples were on the table. I ate two apples. table. I ate some apples. table. I ate two apples. How many apples are on Then there were three Then there were three different Taken from the table now? apples. How many apples. How many apples 5 – 2 = ? apples did were on the table before? ? – 2 = 3 I eat? types of 5 – ? = 3 problems. Both Addends Unknown 1 Total Unknown Addend Unknown Three red apples and Five apples are on the Grandma has five flowers. two green apples are on table. How many can she put in Put the table. How many Three are red and the her red vase and how Together/ apples are on the table? rest are green. How many in her blue vase? Take Apart 2 3 + 2 = ? many apples are green? 5 = 0 + 5, 5 = 5 + 0 3 + ? = 5, 5 – 3 = ? 5 = 1 + 4, 5 = 4 + 1 5 = 2 + 3, 5 = 3 + 2 Difference Unknown Bigger Unknown Smaller Unknown (“How many more?” (Version with “more”): (Version with “more”): version): Julie has three more Julie has three more apples Lucy has two apples. apples than Lucy. Lucy than Lucy. Julie has five Julie has five apples. has two apples. How apples. How many apples How many more apples many apples does Julie does Lucy have? does Julie have than have? Lucy? (Version w ith “fewer”): Compare 3 (Versio n with “fewer”): Lucy has 3 fewer apples (“How many fewer?” Lucy has 3 fewer apples than Julie. Julie has five version): than Julie. Lucy has two apples. Lucy has two apples. apples. How many apples does Julie has five apples. How many apples does Lucy have? 5 – 3 = ?, ? + 3 = 5 How many fewer apples Julie have? does Lucy have than 2 + 3 = ?, 3 + 2 = ? Julie? 2 + ? = 5, 5 – 2 = ? 8
Your child needs to memorize basic facts. Operations and Algebraic Thinking Mental Math Strategies through 20 *Plus 0 9+0=9 *Counting On/Counting Back 7+2~ 7, 8, 9; 12-3~ 12, 11, 10, 9 *Counting Up to Subtract 14- 9~ 9… 10,11,12,13,14…answer is 5 *Doubles 7+7= 14 ~ Doubles Plus 1 7+8= 7+7+1 *Commutative Property 9+6= 6+9 9+6=15 so 6+9=15 *Relationship Between Addition and Subtraction 8+4=12 so 12-8+4 *Making 10 8+6= 8+2+4= 10+4= 14 *Decomposing a Number Leading to a Ten 13-4= 13-3-1= 10-1=9 9
Lucy had 39 stickers and her mom gave her 24 more stickers. How many stickers does Lucy have now? (Solve and show your work) 10
. Traditional Algorithm is not taught until 3 rd grade Here are some common mistakes that students make, and that test- makers take advantage of… 29 + 14 1 29 29 29 +14 +14 +14 43 313 16 (correct) (incorrect- failed to “carry the “one” or added all the numbers together) 11
Direct Modeling 12
Base 10 13
100’s Chart 14
Open Number Lines 15
Number Strings (Decomposing) 16
Adding in Chunks (Incrementing) 17
Compensation 18
Subtraction Lucy had 54 stickers and she gave her mom 29 of them. How many stickers does Lucy have now? *Students will often use related addition strategies when solving subtraction strategies (29 + __ = 54) 19
common mistakes… 34-19= __ 2 14 34 34 -19 -19 15 25 (correct) (incorrect- subtracted from the bottom up in the ones place) 20
Direct Model 21
Base 10 22
Hundreds Chart 23
Open Number Line 24
Number Strings (Decomposing) (leaving first number whole, decomposing second number) 25
Incrementing 26
Compensating 27
Sample 2nd grade test question… In the question, “There were 67 boys ad 54 girls on the playground. How many kids were on the playground?” a second grade student started with 60 + 50 =110. What will they do next? a. 60 + 4 c. 7 + 4= 11 b. 60 + 11 d. 50 + 7 28
Another Second grade sample question… 29
Sample 3 rd grade test question… Fill in the blanks below with whole numbers greater than 1 that will make the number sentences true. 1. 63 ÷ ___ = 7 2. 63 = 21 × ___ 3. 21 = ___ × 7 4. 7 × (___ × ___ ) = 21 × 7 5. (21 × 3) ÷ ___ = 7 Part B: If the product of two whole numbers greater than 1 is 63, what could the two whole numbers be? _______, ________ 30
Helping Your Child at Home RELAX! Be Patient *You are a “guide” - don’t take over for your child *Believe that your child can be successful * Expect your child to work hard to learn mathematics *Always show all your work- have your child explain the problem and his thinking out loud *Talk about why solutions are correct and incorrect *Help your child connect math with daily life *Be supportive of methods your child shares from school 31
Thank you for reading!! (feel free to e- mail your child’s teacher if you have any questions) 32
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