Model Multiplication by Multiples of 10
Model Multiplication by Multiples of 10 is a Grade 3 math skill from Eureka Math connecting place value to multiplication. To model a × (b × 10), arrange a groups of b tens disks on a place value chart. For example, 3 × 20 = 3 groups of 2 tens = 6 tens = 60. The place value chart makes it visible that multiplying by a multiple of 10 shifts the answer one place to the left. Third graders use this model to build toward fluency with larger multiplication facts and understand why multiplying by 10 appends a zero.
Key Concepts
To model the multiplication of a single digit number by a multiple of 10, such as $a \times (b \times 10)$, you represent $a$ groups of $b$ tens disks on a place value chart.
Common Questions
How do you model multiplication by a multiple of 10 on a place value chart?
Represent the multiple of 10 as tens disks. Place a groups of b tens disks on the chart. Count the total tens disks. Convert the tens to a standard number.
How does 4 × 30 look on a place value chart?
30 = 3 tens. So 4 × 30 = 4 groups of 3 tens = 12 tens = 120. On the chart, you have 12 disks in the tens column, which equals 120.
Why does multiplying by a multiple of 10 give a product ending in zero?
A multiple of 10 contains a factor of 10. Multiplying by 10 shifts each digit one place to the left, which always results in a zero in the ones place.
What basic fact strategy underlies multiplication by multiples of 10?
Multiply the non-ten factor by the digit in the tens (the basic fact), then attach the appropriate number of zeros. For example, 6 × 40: basic fact 6 × 4 = 24, attach one zero = 240.
In which textbook is Model Multiplication by Multiples of 10 taught?
This skill is taught in Eureka Math, Grade 3.