Multiplication Tables
Hong Kong
Stage 1
Multiplication x9
Lesson
9 is sometimes called a magical number because it has so many cool properties!
There are heaps of patterns and tricks we can use to help us learn the 9 times tables and we're going to look at them now.
Of course, just like all multiplication tables, you can always count up. In this case we would need to count up by nines.
Now Let's Get Tricky with 9 Times Tables!
Summary
In this video, we saw that:
- $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.
Hand Calculator for Your Nines
Although it's important to understand that multiplying by $9$9 means that there are nine equally sized groups, there is a really cool shortcut you can use to help you solve questions in the nine times tables. Watch this video to see how.
Worked Examples
Question 1
$5\times9$5×9
Question 2
$9\times2$9×2
Question 3
$9\times0$9×0