Upload
oneida
View
31
Download
1
Tags:
Embed Size (px)
DESCRIPTION
Everyday Mathematics Family 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 21 st century. - PowerPoint PPT Presentation
Citation preview
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