Oakland A’s 2008 Math Educational Program
5th-8th Grade Workbook
How to calculate a pitchers ERA
In baseball, a statistic called an Earned Run Average or ERA is used to
track the average number of earned runs a pitcher allowed for every
nine innings. The lower a pitcher’s ERA, the less number of runs a
pitcher has given up in the innings he has pitched. To calculate a
pitchers ERA you multiply the total number of earned runs (ER) by nine
and divide the result by total innings pitched (IP).
The equation is:
(ER) x 9
(IP)
=ERA
Sample Problem:
Rich Harden gave up 3 earned runs in 12 innings pitched against
the Boston Red Sox. What is Harden’s ERA against the Red Sox?
ER= 3
IP= 12
3x9 27
12 = 12 = 2.25
Harden’s ERA against the Red Sox is 2.25
Players ERA Problems:
Greater than, less than or equal to (>, <, =):
1. Gaudin’s ERA of 4.42 ____ DiNardo had 60 ER’s and pitched
131.1 innings.
2. Harden had 7 ER and pitched 25.2 innings ____ Street had 16 ER
and pitched 50 Innings.
3. Calero has allowed 30 ER in 54 innings pitched ____ Embree’s 3.97 ERA with 68 innings pitched
4. Hits: Eric Chavez’s .240 AVG in 341 at bats _____Travis Buck’s .288 AVG in 285 at bats.
How to calculate a players Batting Average
The statistic kept on players when they are at bat is called a batting
average (AVG). It represents the amount of hits per plate appearances an
individual player accumulates. To compute a batting average you divide
the number of base hits (H) by the total number of at bats (AB).
The equation is:
(H)
=AVG
(AB)
Sample Problem:
In 2007 Kurt Suzuki carried an average of .275 in 502 at bats.
How many hits did Suzuki have?
AB= 502
AVG= .275
(H)
H= (.275)(502)
H= 138.05
502 = .275
Suzuki had 138 hits in 2006.
Problems:
1. If Eric Chavez had 82 hits in 341 at bats for the season, what was his batting average?
2. Travis Buck had a batting average of .288 and had 82 at bats. How many hits did Travis have?
3. In 2007 Mark Ellis had 90 hits in 307 at bats on the road, and had 71 hits in 276 at bats at home. Did Mark hit better on the road or at home in 2007?
4. Write out the players in the order of who had the best batting average. Kurt Suzuki has 88 hits in 338 at bats, Jack Cust has 101 hits in 395 at bats, and Jack Hannahan has a batting average of .262 for
the season.
How to calculate a players Win/Loss Average
The win/loss average is computed by dividing the number of games won
(W) by the total number of decisions (TD).
The equation is:
(W)
(TD)
= win/loss average
Sample Problem:
In 13 starts, Chad Gaudin had 16 wins and 12 losses.
What was his win/loss percentage?
W= 16
TD= 28
Win/Loss average = 16
16
=.571
28
28
Win/Loss average = .571
Gaudin had a 57% win/loss average in 31 starts.
Problems:
1. If Joe Blanton has 42 wins and 34 losses in his 4-year career, what is Blanton’s win/loss average?
2.Huston Street came in to pitch 23 times; he won 5 games and lost 2. What was his win/loss average?
3.Rich Harden had 8 wins and 4 losses at home. On the road he had 7 wins and 5 losses. Was his win/loss average better at home or on
the road?
4.Before the All-Star break, Chad Gaudin had 8 wins and 3 losses, Joe Blanton had 8 wins and 5 losses and Lenny DiNardo had 5 wins and
3 losses. What was each player’s win/loss percentage? Also put the players in order of who had the best win/loss average before the
All- Star break?
More Math Fun:
1. Write each (x,y) coordinate in the box.
X
Y
1.
2.
3.
4.
5.
6.
2. Find the missing number to see the secret message.
1. 11x____=11
D
2. ____x6=18
3. 12x8=____
H
A
5. 6x7=____
S
6. ___x9=18
7. 10x____=0
8. 1x____=9
L
L
O
9. 5x5=____
E
10.____x5=60
N
13. ____x1=8
14. 12x____=84
K
A
11.11x____=55
12. 12x2=____
A
C
15.____x6=60
T
____________________________
9 96 8 2 7 12 1
4. 5x____=30
I
____________________________________
5 4
3 0 25 10 6 24 42
16. 9x____=36
T
Averages, Fractions and Percents:
1. The table shows the number of runs the A’s scored in the first 5 baseball games of the season. What is the average or mean number
ofpoints for the first five games?
Game
1 2 3 4 5 Runs
6
8
3
7
6
2. What is the average (mean) number of homeruns hit by all the following players?
Johnson: 12, Suzuki: 11, Cust: 26, Buck: 7, Barton: 1, Ellis: 2
3. Write the each players slugging percentage as a fraction and
a percent.
A. Bobby Crosby: .341
B. Jack Cust: .504
C. Daric Barton: .361
D. Kurt Suzuki: .408
4. If Alan Embree pitched for 2 2/3 innings, and Huston Street pitched for 1 1/3 innings, what is the total number of innings they pitched?
How to calculate a players Slugging Percentage
The slugging percentage (SLG) is found by dividing the total number of
bases (TB) of all base hits by the total number of times at bat (AB).
The equation is:
(TB)
= slugging percentage
(AB)
The total number of bases (TB) is calculated by assigning the following
numbers to each base hit:
Single = 1
Double = 2
Triple = 3
Home Run = 4
Sample Problem
Mark Ellis hit for the cycle in 5 at bats. What was his slugging
percentage for that game?
TB= Cycle=(1single)+(1 double)+(1 triple)+(1 home run) = 1+ 2 + 3 + 4
10
= 2.00
5
Ellis’ slugging percentage was 2.00
Problems:
1. Daric Barton ended the season with 109 hits and 206 total bases in 462 at bats. What was his slugging percentage?
2. Eric Chavez has 1026 total hits. Chavez has 599 singles, 221 doubles, 16 triples and 190 home runs. How many total bases does Eric have?
3. Bobby Crosby has a slugging percentage of .426 in 545 at bats. How
many total bases does Crosby have?
4. Jack Cust has 305 total bases in 715 at bats. What is Cust’s
slugging percentage?
Answer Sheet
Players Batting
Average Problems:
Players ERA Problems:
1. ________
2. ________
3. ________
4. ________
Players Win/Loss
Average Problems:
1. ________
2. ________
3. ________
4. ________
Averages, Fractions
and Percents:
1. ________
2. ________
3. ________
4. ________
1. ________
2. ________
3. ________
4. ________
More Math Fun:
1.
2.
3.
4.
5.
6.
7.
8.
________
________
________
________
________
________
________
________
9. ________
10. _______
11. _______
12. _______
13. _______
14. _______
15. _______
16. _______
X
Y
Slugging Percentage
Problems:
1. ________
2. ________
3. ________
4. ________
Name _____________________________________________________
School__________________________City_______________________
Grade Level________________________________________________
CONGRATULATIONS!