Everyday Mathematics Family Night
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Transcript of Everyday Mathematics Family Night
Everyday MathematicsFamily Night
September 22, 2010
Background
• Developed by the University of Chicago School Mathematics Project
• Based on research about how students learn and develop mathematical power
• Provides the broad mathematical background needed in the 21st century
You can expect to see…
• …a problem-solving approach based on everyday situations
• …an instructional approach that revisits concepts regularly
• …frequent practice of basic skills, often through games• …lessons based on activities and discussion, not a
textbook• …mathematical content that goes beyond basic
arithmetic
A Spiral Approach to Mathematics
• The program moves briskly and revisits key ideas and skills in slightly different contexts throughout the year.
• Multiple exposure to topics ensures solid comprehension.
• Strands are woven together-no strand is in danger of being left out.
More Spiraling…
• Mastery is developed over time. The Content by Strand Poster depicts the interwoven design.
• Homework problems will have familiar formats, but different levels of difficulty.
Everyday Mathematics Website
• Each student will receive login for home access. (available from your child’s teacher)
• Website contents: games and student reference book (SRB)
• http://www.everydaymathonline.com
Something to think about…
• “Even though it doesn’t look quite like what you did when you went to school, yes, this is really good, solid mathematics.”-2001
Education Development Center Inc.
Focus Algorithms
Algorithm slides created by Rina Iati, South Western School District, Hanover, PA
Partial Sums
An Addition Algorithm
268+ 483
600Add the hundreds (200 + 400)
Add the tens (60 +80) 140Add the ones (8 + 3)
Add the partial sums(600 + 140 + 11)
+ 11751
785+ 6411300Add the hundreds (700 + 600)
Add the tens (80 +40) 120Add the ones (5 + 1)
Add the partial sums(1300 + 120 + 6)
+ 6
1426
329+ 9891200 100
+ 18
1318
An alternative subtraction algorithm
In order to subtract, the top number must be larger than the bottom number 9 3 2
- 3 5 6 To make the top number in the ones column larger than the bottom number, borrow 1 ten. The top number become 12 and the top number in the tens column becomes 2.
12
2
To make the top number in the tens column larger than the bottom number, borrow 1 hundred. The top number in the tens column becomes 12 and the top number in the hundreds column becomes 8.
12 8
Now subtract column by column in any order
5 6 7
Let’s try another one together
7 2 5
- 4 9 8 To make the top number in the ones column larger than the bottom number, borrow 1 ten. The top number become 1515 and the top number in the tens column becomes 1.
15
1
To make the top number in the tens column larger than the bottom number, borrow 1 hundred. The top number in the tens column becomes 11 and the top number in the hundreds column becomes 6.
11 6
Now subtract column by column in any order
2 7 2
Now, do this one on your own.
9 4 2
- 2 8 7
12
313 8
6 5 5
Last one! This one is tricky! 7 0 3
- 4 6 9
13
9 6
2 4 3
10
Partial Products Algorithm for Multiplication
Calculate 50 X 60
67X 53
Calculate 50 X 7
3,000 350 180 21
Calculate 3 X 60
Calculate 3 X 7 +Add the results 3,551
To find 67 x 53, think of 67 as 60 + 7 and 53 as 50 + 3. Then multiply each part of one sum by each part of the other, and add the results
Calculate 10 X 20
14X 23
Calculate 20 X 4
200 80 30 12
Calculate 3 X 10
Calculate 3 X 4 +Add the results 322
Let’s try another one.
Calculate 30 X 70
38X 79
Calculate 70 X 8
2, 100 560 270 72
Calculate 9 X 30
Calculate 9 X 8 +Add the results
Do this one on your own.
3002
Let’s see if you’re right.
Partial Quotients
A Division Algorithm
The Partial Quotients Algorithm uses a series of “at least, but less than” estimates of how many b’s in a. You might begin with multiples of 10 – they’re easiest.
12 158There are at least ten 12’s in 158 (10 x 12=120), but fewer than twenty. (20 x 12 = 240)
10 – 1st guess
- 12038
Subtract
There are more than three (3 x 12 = 36), but fewer than four (4 x 12 = 48). Record 3 as the next guess
3 – 2nd guess- 36
2 13
Sum of guesses
Subtract
Since 2 is less than 12, you can stop estimating. The final result is the sum of the guesses (10 + 3 = 13) plus what is left over (remainder of 2 )
Let’s try another one
36 7,891100 – 1st guess
- 3,6004,291
Subtract
100 – 2nd guess
- 3,600
7 219 R7
Sum of guesses
Subtract
69110 – 3rd guess
- 360 331
9 – 4th guess
- 324
Now do this one on your own.
43 8,572100 – 1st guess
- 4,3004272
Subtract
90 – 2nd guess
-3870
15199 R 15
Sum of guesses
Subtract
4027 – 3rd guess- 301
1012 – 4th guess
- 86