Transcript 3rd Grade Math Targets - Davis School District

rd
3 Grade
Math Skills & Strategies
Problem of the Day
Strategies
1.Find (Identify the question)
2.Know (Gather Information)
3.Strategies:
Draw a picture
Make an organized list
Make a table
Make a graph
Act it out
Look for a pattern
Try, check, revise
Write an equation
Use reasoning  ALWAYS!! 
Work backwards
Solve a simpler problem
4. Show the problem (work it out)
5. Solution (the answer to the
problem)
6. Answer (in a complete sentence)
7. Check for reasonableness,
evaluate (do the opposite:
add/subtract, multiply/divide, etc.)
Word Problem Strategies
•If labels are the same =
ADD or SUBTRACT!
•If labels are different =
MULTIPLY or DIVIDE!
1.Read the word problem.
2. Find and underline the question.
3. Box out key words & vocabulary
words.
4.Circle numbers you need, underline
labels, mark out any distractors.
5.Choose your strategy.
6.Solve the problem (show your work!)
7.Prove your answer.
•Watch for 2-step problems!
•Watch for EXTRA or MISSING information!
•Check answer for reasonableness!
Place Value
Standard Number Form: 43,621
Word Form: Forty-three thousand, six hundred twenty-one
Expanded Notation: 40,000 + 3,000 + 600 + 20 + 1
Pizza Place Value: 43,621 (line the numbers up correctly and it will
40,000
look like a slice of pizza!)
3,000
600
20
1
HTO Chart: 100TH 10TH TH H T O
4 3 6 2 1
Digit: Number
Value: The worth of something.
Patterns
A
Repeating Pattern:
B
C
A
____
Stem
____
Growing Pattern:
1 Month
2 Months
T-Chart: ----------------------------------
+2
^
3 Months
4 Months
# of months
# of leaves
1
2
3
4
5
Number Pattern: 2, 4, 6, 8, __, 12, 14….
Teepee: ^
5 Months?
Rule: example=(+2)
1
2
3
4
?
Money
1 cent
“Hairy
Money”
5 cents
10 cents 25 cents
50 cents
.
Currency: the money that is
used in a country.
Telling Time
Analog: physical measurement
Digital: electronic signal
Quarter Before: 15 minutes before the hour
Quarter After: 15 minutes after the hour
1.
Look at the hour hand (shortest) and say the number. If it is between
the numbers you say the lowest number or the number before.
2.
Look at the minute hand (longest), count by 5’s and say the number. If
it is on 60, say “o’clock”.
Addition with Regrouping
The answer to an addition problem is called the SUM.
475
+ 136
_____
611
1. Put big number on top to help remember for subtraction.
2. Make sure the numbers are lined up (ones with ones, tens with
tens…)
3. Look at the ones place; if the two numbers equal ten or more you
will regroup.
4. Bring the ones place down to the ones place and carry the ten to
the tens place.
5. Look at the tens place and add the regrouped number.
6. Add all the numbers in the tens place. If the numbers equal ten or
more you will regroup.
7. Repeat steps 3 and 5.
Sum, How many are there, Added/Plus, Total, In all, Altogether, And…
Subtraction with Regrouping
“More on top, don’t stop!
More on the floor, go next door!”
“Numbers the same, zeros the game!”
The answer to a
subtraction
problem is
called the
DIFFERENCE.
How many more/less, How many are left, Spent, Difference…
73
-29
------44
1.
2.
3.
4.
5.
6.
7.
8.
9.
Place the bigger number on top.
Make sure numbers are lined up (ones with ones, tens with tens, etc.)
Start at the ones place and look at the numbers to see if you can subtract
without regrouping.
If the top number is bigger, you can just subtract.
If the top number is smaller (less than) the bottom number, you have to
regroup.
Take one ten from the tens place and cross it out (it becomes one less)
(example: 3 turns into 2).
Add the ten to the ones place.
Subtract the ones.
Look at the tens & repeat steps 3-8.
Number Lines
Look for the RULE!
•Try numbers until you find the rule.
31, 37, ___, 49
(Rule +6)
(Rule -5)
25
___
15
10
Don’t forget your teepees! (^)
2D & 3D Shapes
The corners
are called
VERTICES.
Face
Edge
Sides
Vertices
Rectangular
Prism
Perimeter
90
90
90
+ 90
-------
Outside – Add ALL of the sides!
Perimeter: the length of the border.
Area
Area: the amount of surface within a certain
space.
Inside – Count what you are
looking for.
* Watch for shaded or NOT
shaded!
Multiplication
Ways to solve:
1.Loops & Groups
The answer to a multiplication
problem is called a PRODUCT.
IIII
IIII
IIII
4
....
3 ....
....
2.
Array
3.
Repeated addition
4.
T-Chart
5.
Gets bigger!
Algorithm (aka “up & over”)
(you have to have your facts
memorized to use this method!)
4 + 4 + 4 = 12
3X4
4X3
3
X4
-----
4
X3
-----
Product, Times, Twice,…
= 12
Greater & Less Than
Greater Than
36 > 29
Less Than
15 < 57
Fractions
Fraction-an equal part of a whole number.
Numerator-tells us how many parts; “UP!”
Denominator-tells us all the equal parts; “DOWN!”
Equivalent-the same of equal.
3
--- are shaded
4
1
--- is not shaded
4
Rounding – Part 1
“Round to the nearest…”
“About how many,,,”
“About”
•Estimate when you don’t need an exact
answer.
•Estimate to check your work.
When you see ESTIMATE or ABOUT,
“round FIRST, then solve”!
Rounding – Part 2
Remember: When it’s in the
middle (5), you round up!
25=30
Find the digit,
Look next door.
Five or higher,
Add one more!
Four or less,
Let it rest!
0,1,2,3,4 = go
to lowest 10
5,6,7,8,9 = go
up to highest 10
93
-38
------
Rounds to
Rounds to
90
-40
-----50
Temperature
F
Boiling
212
Freezing 32
0
C
100
Fact Families
Addition/Subtraction fact families are found by:
Starting with a simple fact. ( 2 + 5 = 7)
Changing the numbers around. (5 + 2 = 7)
Writing the Inverse operations for both.
(7 - 2 = 5 & 7 - 5 = 2)
Multiplication/Division fact families are found by:
Starting with a simple multiplication fact. ( 3 x 9 = 27)
Changing the multiplicands around. (9 x 3 = 27)
Writing the Inverse operations for both.
(27 / 3 = 9 & 27 / 9 = 3)
Division
Gets smaller!
Look for these words to divide:
12 / 4 = 3
Separate, give, each, equal…
The answer to a division problem
is called a QUOTIENT.
Loops & Groups
IIII
Division Monster
Separate, Equal, Half, Each (in the question)…
IIII
IIII
IIII
Array
IIII
IIII
12
IIII
Measurement
12 inches = 1 foot = “your ruler” or “piece of paper”
3 feet = 36 inches = 1 yard = “yard stick”
1 meter = “light on ceiling”
1 mile = 5,280 feet = “school to Wal-Mart”
1 inch = “end of finger”
1 cm = 0.01 meter = “width of pinky”
Congruence
Congruent-same size AND
shape.
Symmetry
Symmetry-one object that when an imaginary line is drawn
through is the same at both ends.
Line of Symmetry-a line that divides a figure/shape into two
mirror images.
Line of Symmetry
Graphs
Paired Numbers
•To make two batches of cookies how many eggs
do you need? For three batches? For four
batches?
•How did you find the number of eggs needed to
make four batches of cookies?
Probability
“More likely than”, “Less likely than”, “Equally likely as”…
Range
The range (answer)
12-24
Lowest number
3
6
X
4
X
The number that only has 1 label.
Highest number
*With range, you
will either multiply
or divide.