3.09 Multiply by 9
Lesson
Are you ready?
Multiplication looks at equally sized groups. Can you solve this problem?
$8\times5$8×5
Learn
$9$9 groups is $1$1 less than $10$10 groups. Let's look at how we can use this to help us learn the $9$9 times tables.
Apply
$5\times9$5×9
Remember!
- $9$9 groups can be thought of as $10$10 groups - $1$1 group.
- When we look at the answers up until $9\times10$9×10, the units have a descending pattern and the tens have an increasing pattern.
- When we add the digits in the answers to the nine times tables until we get a single digit, that digit is ALWAYS $9$9.