Math Trailblazers Homework Help-Fourth Grade
Unit 11
Dear fourth grade parents,
Thank you so much for coming to this page to find out more about the math your child is
bringing home. Every page that your child could bring home is listed in this chart. Do not expect your
child to bring every page home. Often a teacher will note that the student already has a healthy
command of a skill, making assignment of homework unnecessary. At other times the teacher may
have a different assignment that (s)he feels is more appropriate.
To use these pages, find the Unit and Lesson numbers on the bottom of your child’s assignment
page or textbook and then click on the corresponding blue link in the table. You will find information
about the skills being practiced and occasionally extra notes will provide background information or
tips on how to extend the activity to make it more or less challenging.
Click links
in this column
Activity
Unit 11 Background Info
Unit 11 DAB p.185
Multiplication facts and working with large numbers
Unit 11 DAB p.186
Using multiples of ten, writing large numbers, calculating
Unit 11 DAB p.187
Multiplication practice and metric measures
Unit 11 DAB p.188
Using rules of divisibility
Unit 11 pages 302-303
Multiplying larger numbers
Unit 11 pages 306-307
More large number multiplication
Unit 11 pages 310-312
Comparing traditional and partial products multiplication
Unit 11 pages 315-316
Estimating products to check calculations
Unit 11 pages 320-321
Comparing traditional and partial products multiplication
To read the small pages more easily, set the image size to 200%.
Please remember that skills in our Trailblazers program are repeated many times during the year. If
your child is struggling with a skill in Unit One it should not be as much of a concern as if your child
continues to struggle with the same skill when you see it reviewed near the end of the book.
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Fourth Grade - Unit 11 – Homework Help
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Unit 11 Background Information for Student Guide pages 302-303, 306-307,
310-312, 315-316 and 320- 321.
Students have been given a variety of strategies for multiplication. They are shown
the standard algorithm. Another strategy (doubling one factor while halving the
other) is one that parents may be unfamiliar with. Using this method we can change
5 x 24 to 10 x 12. We also show children the partial products method. This method
shows all steps in the multiplication calculation. In the example at the right each of
the following steps is visible. 4 x 6, 4 x 30, 10 x 6 and 10 x 30. Some children prefer
this to the standard algorithm because they can see all the steps.
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Partial
Products
Method.
36 .
x14 .
24 .
120 .
60 .
300 .
504 .
Fourth Grade - Unit 11 – Homework Help
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Multiplication
The flashcards for this unit (square numbers) should be
review. The square number facts were introduced in
third grade and reviewed again in Unit 4 of fourth
grade. If there are facts that your child does not
know, work on them one at a time.
Larger Numbers
Question 3 does not require students to add all the
numbers. For example, to get 49,000 when adding 2 the
number has to end in 98 because 98 + 2 = 100. Only two
numbers end in 98 so those are the only two that need
to be checked.
In Part 4 students need to make numbers that are “a
little larger or a little smaller.” The students determine
how much “a little” is. For example, 999,999 could be a
little smaller but so could 999,000.
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Multiplying with Multiples of Ten.
Students should remember that they can multiply the
significant digits and then add as many zeros as the
combined total of zeros in the two factors.
Add and Subtract Larger Numbers
Students do not need to use paper and pencil for all of
these. For example, Part 5 calculation B can be
completed as 300 – 200 combined with 40 – 35.
Calculation C can be done as 58 – 50 + 1.
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Fourth Grade - Unit 11 – Homework Help
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Multiplying with Multiples of Ten.
Students should remember that they can multiply the
significant digits and then add as many zeros as the
combined total of zeros in the two factors.
Metric Measurement Names.
Since many adults may not be familiar with metric units,
the correct answers are presented below.
The height of a room is about 3 meters.
The length of a sofa is about 20 decimeters. (2
meters seems a more reasonable measure.)
The width of a sharp pencil point is about 2
millimeters.
The length of a pencil is about 14 centimeters.
The distance from Chicago to Dallas is about 1500
kilometers.
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Divisibility Rules
All even numbers are evenly divided by 2.
If the sum of the digits is evenly divided by three then
the entire number can be evenly divided by 3.
If a number can be evenly divided by both two and three,
then the number can be evenly divided by 6.
If the sum of the digits is evenly divided by nine then the
entire number can be evenly divided by 9.
In Part 11 calculation A, the product should be evenly
divided by nine since 156 was multiplied by nine.
1 + 4 + 0 + 4 = 9 which is evenly divided by nine. It is
likely that the product is correct.
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Fourth Grade - Unit 11 – Homework Help
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Unit 11 Pages 302-303
Q 1-19 Students may use a variety of
strategies for completing these
calculations. See above.
Q 20–24 Q 20 – 24 These are rather straight
forward multiplication problems for adults
but that may not be the case for kids. Try
to ask questions such as, “What do you
know?” or “How far can you get with this
calculation?”
Q 25–30 These can have only one correct
product.
Q 31 Some possible correct products for this
calculation include…
1 x 80, 2 x 40, 4, x 20, 5 x 16.
Q 32 Some possible correct products for this
calculation include…
240,000 x 1, 120,00 x 2, 80,000 x 3
60,000 x 4 48,000 x 5 40,000 x 6
Q 33–38 See notes for questions 1-19 above.
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Unit 11 Pages 310 - 312
Q 1 In this unit the students were introduced
to our traditional algorithm (pattern) for
multiplying whole numbers. The book calls
it “Compact Method”. Some students will
still prefer to use the Partial Products
Method because they can see all the parts.
Q 2-13 We encourage students to practice the
Compact Method with these calculations so
they get a good comparison with the
Partial Products Method.
Q 14-18 These are rather straight forward
multiplication problems for adults but that
may not be the case for kids.
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Unit 11 Pages 315-316
Q 1-2 These two calculations help student
remember the steps for the Partial
Products Method.
Q 3 Crazy 70 x 40 = 2800
Q 4 Could be 30 x 40 = 1200
Q 5 Crazy 20 x 34 =640
Q 6 Crazy 6 x 25 = 150 so 60 x 25 = 1500
Q 7 Could be 10 x 55 = 550 A better estimate
would be “Greater than 550.”
Q 8-15 The Partial Product Method is
reviewed for pages 302-303 above.
Q 16-19 These are rather straight forward
multiplication problems for adults but that
may not be the case for kids. See
background notes.
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Unit 11 Pages 306-307
Q1
See notes for questions 1-19 above.
Q 2–5 These are rather straight forward
multiplication problems for adults but that may
not be the case for kids.
Q 6-23 Children are expected to use a variety
of strategies to complete these calculations.
Different strategies work best with different
numbers. See notes above.
Q 24 A good strategy would be 6 x 400
Q 25 A good strategy would be 3 x 3000
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Fourth Grade - Unit 11 – Homework Help
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Unit 11 Pages 320-321
Q 1 Helps the student compare the two
different methods for multiplying multidigit numbers.
Q 3-10 These can be done using either of the
two methods. The student should choose
the one that makes the most sense to him
or her.
Q 11-16 These are rather straight forward
multiplication problems for adults but that
may not be the case for kids.
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Fourth Grade - Unit 11 – Homework Help