Download Topic 5 Review Sheet

Math Review
Topic 5: Multiplication Facts
Domain: Operations and Algebraic Thinking
Common Core Standards covered:
Identify arithmetic patterns, and explain them using properties of operations.
Multiply one-digit whole numbers by multiples of 10 in the range 10-90 using
strategies based on place value and properties of operations.
Solve two-step word problems using the four operations. Represent these problems
using equations with a letter standing for the unknown quantity. Assess the
reasonableness of answers using mental computation and estimation strategies.
Multiples – the product of a number and other whole numbers. Another word
for multiples is skip counting. Multiples of 3s: 3, 6, 9, 12, 15, 18, 21,
24, 27, 30
2 as a factor:
*Multiples of 2s are even numbers. 2, 4, 6, 8, 10, 12, 14, 16, 18, 20
*The 2s are called the doubling factor because the product is the
same as doubling the factor. Ex: 2 x 5 = 10 (double 5: 5 + 5 = 10)
5 as a factor:
*Each multiple of 5 ends in 0 or 5. 5, 10, 15, 20, 25, 30, 35, 40, 45, 50
*If 5 is multiplied by an even factor, the product will end in 0.
*If 5 is multiplied by an odd factor, the product will end in 5.
9 as a factor:
*9, 18, 27, 36, 45, 54, 63, 72, 81, 90
*The ones digit decreases by 1 each as the tens digit increases by 1
each time.
*The tens digit is one less than the factor being multiplied by 9.
Example: 8 x 9 = 72 The tens place of the product is one less than
the 8.
*Adding the 2 digits of multiples together will give you a sum of 9.
Example: 9 x 5 = 45 (4 + 5 = 9)
Identity (One) Property of Multiplication – multiplying a number and 1, the
product will be that number. Examples: 5 x 1 = 5, 99 x 1 = 99
Zero Property of Multiplication – multiplying a number and 0, the product is
always 0. Examples: 8 x 0 = 0, 125 x 0 = 0
10 as a factor:
*All multiples of 10 end in zero. 10, 20, 30, 40, 50, 60, 70, 80, 90, 100
*Write the factor you are multiplying by 10. Then add a zero to the
right of that factor. Example: 5 x 10 = 50, 10 x 7 = 70
Multiplying by multiples of 10:
* Multiply the factor by the tens place of the multiple of 10. Then
add a zero to the right of that product. Example: 5 x 30 = 150
Solve Two-Question Problems:
* Sometimes you must use the answer to one problem to solve another
problem.
Example: Four girls and five boys went to the movies. How many
children went to the movies? Children’s tickets cost $5. What was
the total cost of the tickets?
1st Step: Solve how children went to the movies. 4 + 5 = 9 children
2nd Step: Find how much the tickets cost. 9 x 5 = $45