3rd GRADE HOMEWORK HELP
PLACE VALUE
multiplication & division
EXPANDED FORM
add value of each digit
400 + 10 + 3
This ARRAY shows three
groups with six in each group.
STANDARD FORM
regular number
413
4 hundreds
value = 400
1 ten
3 ones
value = 10 value = 3
WORD FORM
how you read the
number
“four hundred
thirteen”
or rows
or row
UNDERSTANDING OPERATIONS
ADDITION
What is the total?
How many altogether?
How many in all?
The sum is....
MULTIPLICATION
in all , total, and
altogether when
groups are equal
Find multiples of...
What is the area?
What is the product?
SUBTRACTION
How many fewer?
How much change?
How many are left?
The difference is...
How many remaining?
0
6
12
18
Multiplication is repeated
addition, so add 3 groups of 6.
6 + 6 + 6 = 18
DIVISION
The quotient is...
Divide into ___ parts.
How many each?
Share
Ways to Think about Division
* Divide 18 into 3 groups (picture)
* Divide 18 into groups of 3
* Missing Factor - What can I multiply
by 3 to get 18?
* Repeated Subtraction -
Answer: Count the number of groups
(bumps) on the number line
divide and conquer
Use to solve long division problems until you are proficient with your
multiplication and division facts.
GET READY: Draw a place value model of the dividend.
STEP 1: In the first column, circle sets of your divisor. When youʼve found
them all, write the number of sets youʼve circled at the bottom of the column
STEP 2: Any left? You have to move any left in that column to the next
column. Remember, for every one you have to move, you will add 10 to the
next column over. If there were no left overs, you would just move to the
next column and start finding sets.
FINISH IT OUT: Keep going! Repeat steps 1 and 2 for every column. If
you have any left over in the ones column, write that number as the
remainder.
ADDITION properties
COMMUTATIVE PROPERTY
Changing the order that the numbers are added does not change the sum.
Ex: 7 + 2 = 9 and 2 + 7 + 9
ZERO PROPERTY OF ADDITION
The sum of any number and zero is that number. Ex: 6 + 0 = 6
ASSOCIATIVE PROPERTY - grouping addends with ( )
Changing the way that addends are grouped does not change the sum.
Ex: (5 + 4) + 8
5 + (4 + 8)
\ /
\ /
9 + 8 = 17 5 + 12 = 17
DIVIDEND
boom-boom subtraction
HUNDREDS
385 – 2
TENS
Use when you need to borrow in subtraction
* Make sure you stack your math problem - DO NOT write side-by-side!
Start with the ones column. If the top number is smaller than the bottom
number, you have to Boom-Boom. Repeat with each column.
5 14 13
1 1
-2 4 9
2 9 4
BOOM,
BOOM
DIVISOR
ONES
X X X X X
ONES: 3-9 - CANʼT DO, SO BOOM BOOM
Now solve ..... 13 - 9 = 4
TENS: 4-5 -CANʼT DO, SO BOOM BOOM
Now solve ...... 14 - 1 = 13 - 4 = 9
HUNDREDS: 5 - 1 = 4 - 2 = 2
1
9
2 R1
MEASURE TO QUARTER AND HALF INCH
BOOM - Put a one above the top number in your column. This adds 10
to that column so you can subtract.
BOOM - Put a one under the top number in the next column. You will
subtract BOTH those numbers from the top number in that column.
PERIMETER & AREA
Perimeter - the distance AROUND a polygon
To find: Measure the sides of a shape then add ALL the sides.
Area - the number of square units it takes to COVER a polygon
To find area of a rectangle or square:
Multiply length (either side) by width (top or bottom)
AREA
sq. units
L
x W
A song to help you remember - to the tune of ʻJingle Bellsʼ
Perimeter, perimeter; add up all the sides.
Area you multiply; How long by how wide.
HEY!
P = 4 + 6 + 4 + 6 = 20 in
A = 4 x 6 = 24 sq in
PROBLEM SOLVING tips
1) WHAT DO I KNOW?
* List the facts or information given in the problem.
* Underline or circle any key words, such as altogether or difference.
* Express the facts in math symbols in a number sentence, if you can.
2) WHAT DO I WANT?
* Describe the goal, what the problem is asking you to find.
3) WHAT CAN I DO?
* Try a tool from the Problem Solving Tool Box.
* Do one step at a time.
4) DOES IT MAKE SENSE?
* When you get an answer, always look back at the original problem one
more time. Check 3 things:
* Does your answer make sense?
* Do you have the correct units (in, sq cm, etc)?
* Can you think of a way to confirm that your answer is correct?
PROBLEM SOLVING TOOL BOX
 Write a number sentence.
 Look for a pattern.
PROBLEM: Bob is building with cubes. He has 6 cubes in row 6, 5
cubes in row 5, and 4 cubes in row 4. If he follows this pattern, how many
cubes would the completed design have?
Make a chart with the information you know, look for a pattern, then use
the pattern to finish the chart.
Row 6 Row 5 Row 4 Row 3 Row 2 Row 1
6
5
4
3
2
1
Look back at the question - How would you find how many cubes are in
the completed design? Mentally add the numbers from the chart = 21
 Make a table.
 Draw a picture or diagram or act the problem out, step by step.
PROBLEM: There are 4 people on a bus. At the first stop, 3 of the
people get off. At the next stop, 5 people get on. How many people are
now on the bus?
SOLVE: Draw 4 stick people to show the first people on the bus. Then, X
out 3 of them for the ones who got off. Last, draw 5 more stick people.
Count your stick people.
 Make an organized chart or list.
PROBLEM: Billy wanted to make a sandwich. As he looked around the
kitchen, he found rye and wheat bread and turkey, ham, and bologna.
How many possible combinations does he have for his sandwich?
SOLVE: Start with one bread - match with each meat. Go to the next
bread and match with each meat. Use abbreviations for each choice.
RT RH RB WT WH WB - 6 combinations
 Work backwards.
 Guess and Check
PROBLEM: The sum of Spotʼs and Palʼs ages is 12. Pal is 2 years
younger than Spot. How old is each dog?
SOLVE: Write number sentences to show the information:
Spot + Pal = 12 and Spot - 2 = Pal
Guess reasonable answers then check to see if they make sense.
Spot 8 + Pal 4 = 12 so does Spot 8 - 2 = Pal 4? NO
Try again - Spot 7 + Pal 5 = 12 so does Spot 7 - 2 = Pal 5 YES
 Use logical reasoning.
telling time helps
READING AND WRITING TIPS
When reading with your child, after each page you should....
CLARIFY
Reread or discuss words or points that were not clear.
PREDICT
What will happen? or What will we learn?
QUESTION
Ask a question for others to answer.
What if...?
How did...?
What would happen if...? Why did...?
What caused....? What might....?
How would you feel if you....? Why is....?
What character traits describe_____?Why do you think....?
When you are finished reading, SUMMARIZE.
Retell what youʼve read.
Reading 20 minutes per night helps your child become a fluent reader!