Tips for Helping at Home
•
Questions to ask:
What is it that you don’t understand (have
the student be specific)?
What about putting things in order?
Could you try it with simpler numbers?
Can you guess and check?
Does this make sense?
What can you do to explain your answer to
show others what you are thinking?
Does your answer seem reasonable?
•
Offer to solve your child’s coordinate mystery
after he or she creates it. If you are unsure of
how to read grid coordinates, your child can help
you.
•
Play Sunken Ships with your child when he or
she brings it home. Your child can teach you the
rules and maybe even some strategies!
•
Keep your eyes open for rectangles in the world
around you—they’re easy to spot. Work with your
child to find particularly large or small (smaller
than an inch on a side) rectangles, rectangles
that are also squares (all sides are equal), and
rectangles that are much taller than most fourth
graders.
Mathematical Emphasis
Investigation 1—Locating Houses and Ships on a
Grid
•
Using positive and negative coordinates to name
and locate points on a grid
•
Calculating distances on a grid based on paths
along grid lines
•
Exploring numerical patterns that represent geo-
metric situations
•
Connecting visual and numerical descriptions of
distances on a grid
Investigation 2—Rectangles, Turns, and Coordi-
nates
•
Applying knowledge of coordinates to locate points
on a computer screen
•
Describing geometric figures such as rectangles
and squares
•
Understanding how
Geo-Logo
commands reflect
the properties of geometric figures
•
Creating and applying patterns and mental arith-
metic strategies to solve turtle geometry problems
•
Using symmetry to place rectangles on a grid and
design complex patterns of rectangles
Websites
http://cms.everett.k12.wa.us/math
http://aimsedu.org/aimskids/ipuzzles/hurkle/hurkle.html
http://math.donnayoung.org/m01/coordnt/4squ.pdf
Software download - ask your teacher for the pass-
word.
http://investigations.scottforesman.com/sunken.html
2-D Geometry
Designing Rectangle Patterns
As a final project in Sunken Ships, students cre-
ate complex patterns, drawing them first on planning
paper, then entering them on the computer using
Geo-Logo.
Their work focuses on:
•
Analyzing
Geo-Logo
procedures and drawings
•
Predicting drawings from commands and com-
mands from drawings
•
Designing rectangle patterns using
Geo-Logo
•
•
•
•
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While observing this work, teachers and parents can
ask students to explain what they are doing:
•
Do they have a plan?
•
Are they exploring to see what happens?
•
Are they able to predict and explain what hap-
pens when the turtle runs a command?
Vocabulary
Ordered pair:
A pair of numbers used to lo-
cate a point on a coordinate grid. The first
number tells how far to move horizontally
, and
the second number tells how far to move verti-
cally
.
Line segment:
a straight line from one point
to another
Vertex:
the place where two or more line seg-
ments come together
X-axis:
the horizontal axis on a coordinate
grid
Y-axis:
the vertical axis on a coordinate grid
Reflection (flip):
creating a mirror image of a
shape by flipping it over
Translation (slide):
sliding a geometric shape
a certain distance in the same direction
Glossary
http://www.amathsdictionaryforkids.com/
Sunken Ships
Object:
two teams try to locate each other’s sunken
ships
Setting up:
Each team secretly draws a sunken ship
on the grid labeled “Our Ship” on the Sunken Ships
Grids sheet. Ships must cover five grid intersections
lying on a vertical or horizontal straight line.
1. The first team starts its search for the other
team’s ship by naming a grid point, such as (-3,
5)
2. The second team checks to see if that point is
on its ship. If it is, it says “Ship.” If not, it gives
the number of units to the nearest undiscovered
point on the ship.
3. The first team records its point on the grid la-
beled “Their Ship.” They write
S
for ship, if it is a
point on the ship, or the number indicating how
far away from the ship the point is.
4. The second team guesses where to start its
search for the first team’s ship by naming a
point.
5. Teams take turns guessing points until they
have both found all five points of
the other’s ship.