Primary Math Update
April, 2011
Dear Moms and Dads,
“Seven or Eleven” was the name of our new dice game last Friday, April 1st. If the teacher was able to roll a combination of seven or eleven using two dice, she won. If the teacher didn’t, then whatever combination a child rolled with two dice, he or she/won. We had a good time seeing if this could happen, and how frequently the teacher could roll a combination of a seven or eleven. Even though there were fewer possibilities for the teacher to win, she did—every time! Hmmmmmm~
Oh, the joys of April Fools and the luck of some trick dice. One of the teacher's dice had all fives on it, and the other one had just twos and sixes—so the only combinations of two addends that could happen with these trick dice were 7 or 11. The other "look-alike" dice the children used had the traditional 1 through 6 on them, so the sum combinations ranged from 2 to 12.
First graders are beginning a new unit, ("Twos, Fives and Tens"), this month which revisits games that help achieve fluency with the 2-addend combinations of 10. Fluency means that when given a single-digit number, students can recall or quickly reconstruct the addend needed to make 10. This work with the combinations of 10 also lays the foundation for exploring new ideas such as counting by 10s, the place value of the teen number, and generating equivalent expressions for numbers up to 20 (e.g., 8 + 5 = 10 + 3). Children are also engaged in "stretching" their thinking by applying what they know about getting to 10 to getting to 20, such as what goes with 3 to get to 20? What goes with 13 to get to 20? What goes with 7 to get to 21? What goes with 3 to get to 100? What goes with 13 to get to 100?
Counting pattern work continues with games and practice activities for counting by twos beginning with an even or odd number, counting by fives beginning with 5 or any number ending with 0 or 5, and counting by tens beyond 100, and also counting by ones "off the decade," such as 3, 13, 23, 33, 43, etc. Backwards counting by ones and skip counting is also part of our math routines each week, which has implications for helping children understand the concept of subtraction, developing fluency with this operation. How far is it from 20 to 13? What's the difference between 20 and 15?
Second graders have finished up a study of fractions and have learned to quite a bit about "fair shares" and dividing things in halves, thirds, fourths, fifths, sixths and eighths. They had practice recording and reading fractional notation, such as ½ , ¼ , 1/3, 2/3 2/4 ¾ , 2/5, 1 ½ , etc. Vocabulary used included: dividing, equal pieces, equal amounts, numerator, denominator, comparison, etc. Several word problems were used for opportunities to see if fair shares could be created with amounts or sets of objects. Children divided shapes into equal amounts or fair shares and recorded the fractional notation for specific shaded amounts of each shape. We had several conversations and explorations to determine the size or relative magnitude of fractions to each other, and where we would place these on a number line. Questions like, is ¼ or ¾ greater? Is ¼ or ½ greater? Where does 1/3 fit into this order? What do you notice about 2/4 and ½ ?
Second graders are furthering their understanding of the concept Odd/Even. The new math unit we have begun is titled "Partners, Teams and Paper Clips." More word problems are asking children to investigate properties of odd and even numbers and how combining odd numbers to odd numbers, or even numbers to even numbers creates even numbers. What happens when we add an even number to an odd number? What happens when we subtract an even number from an even or odd number? Are there any patterns or rules you can find that seem to be true and work for all situations?
This unit presents your second grader with opportunities to engage with ideas that lay a foundation for algebra. Seven and eight-year-olds can and do think algebraically. Part of the work of Grade 2 is helping students learn to verbalize those thoughts and consider such questions as these: Is this statement always true? Does it work for all numbers? How can we know? Such discussion allow students to engage with generalizations about numbers and operations, while establishing a foundation for meaningful use of algebraic notation in the future. Second graders are also articulating generalizations about subtraction in addition to their work with odd/even ideas.
All students in first and second grade have been working on ESTIMATION. We've been training our eyes to get a "sense" of what ten objects looks like. Using a group of ten, we've learning determine about how many groups of ten we see in a jar of objects or in a collection on the floor, or drawings of fixed objects repeated on a page. We've read a big book titled Great Estimations by Bruce Goldstein. We had so much fun with this book, that I found another book by the same author, Greater Estimations!
A Reminder About Math Homework: Math homework is sent home every Thursday (unless otherwise notified via email parent list). Math homework is due the following Monday, so children have the weekend to complete it. Homework at this level should be something that your child can do on his or her own, with minimal support from you. It is not meant to be a time for further challenge, but rather a time to rehearse something that has been taught, and possibly mastered—a review of a skill that should be fluent or almost fluent. It's also a way for parents to see what we've been up to in math class, and your child's increased independency with number concepts, skills and problem-solving situations.
This week's homework (Thursday, April 7) will be accompanied by the Family Letter provided by the Investigations math program at the beginning of each new math unit, to further explain the math skills, concepts and learning opportunities your child is engaged with during math lessons.
There will be no math homework sent home Thursday, April 14, since the following week will be vacation. Math homework will continue through the middle of May, with the last homework assignment sent home on Thursday, May 12, and due on Monday, May 16.
Sincerely,
Brenda
