Greater/Lesser Than

Background 

Now that we have a number line where we have numbers all in a line, we can start talking about numbers that are greater (i.e. bigger) and those that are lesser (i.e. smaller).

Question 

Is 30 bigger than 10? How do I express that using math symbols?

Answer 

Yes it is. 30 > 10

Analysis  

Let's look at a piece of a number line:



Let's just look at the numbers 10, 20, 30, and 40. Notice that as we move to the right along the number line, the numbers get bigger. This is true all along the number line, and so any number that is to the right of another number on the number line is greater. We can also say that any number that is to the left of another number on the number line is lesser.

Let's mark the 10 (in red) and the 30 (in green) on the number line:



The green 30 dot is to the right of the red 10 dot, so 30 is bigger than 10. We can also say it the other way, that 10 is less than 30.

So let's talk about how to write it using math symbols.

I'm going to write the two numbers and leave a place for a symbol for "greater than":

30 ___ 10

Teachers I've had would talk about a hungry fish that lurks between those two numbers. It can only eat one of them and it wants to eat the bigger of the two. The mouth can either be turned to the left > or to the right <. In our case, we have:

30 > 10

and we say "30 is greater than 10".

We can also write it the other way:

10 < 30

and we say "10 is less than 30".

For more information check out these links (comment to add your favourite link): 

https://www.themeasuredmom.com/less-than-greater-than-math-activity-using-toys/

Where might you have come from? 

Fact-orials Index

Graphing:

• Number Line

Where might we go?

Associated Operations:

• Absolute Value

Relations:

• Greater/Lesser Than and Rational Numbers
• Equality
• Inequality