Hello! In our last session, we focused on breaking down 4-digit numbers into their parts with expanded form. Your child now has a great understanding of how numbers are built from thousands, hundreds, tens, and ones.
Today, we will build on this solid foundation to explore a very simple but important idea: a number's immediate neighbours. We will learn the names for the number that comes just before (predecessor) and the number that comes just after (successor). This final lesson for today will wrap up our foundational work on 4-digit numbers and set the stage for comparing and ordering them tomorrow.
What are Successors and Predecessors?
These might sound like big words, but the idea is very simple.
- The successor is the number that comes just after a given number. Think of it as what you get when you count one step forward.
- The predecessor is the number that comes just before a given number. It's what you get when you count one step back.
The rule to find them is straightforward:
- To find the successor, you add 1.
- To find the predecessor, you subtract 1.
The following resource explains these two concepts very clearly with examples. Please read through these definitions with your child.
Successor and Predecessor of 4-Digit Numbers (Examples+Worksheet+Ans)
This resource from Math-only-Math provides simple definitions and examples for both successor and predecessor.
Please read the sections What is Successor? and What is Predecessor?. Focus on the core idea: successor is "number + 1" and predecessor is "number - 1".
The table below provides a great visual summary of this concept. You can use it to show your child how the predecessor, the number, and the successor line up.
A Fun Way to Practice
Here’s a simple activity you can do together, adapted from a teacher's guide, to make this concept more concrete and fun:
- Stand next to your child, with some space on the other side of them.
- Ask your child to pick a 4-digit number and say it out loud (for example, "3,542!"). They are the "main number".
- You then stand on one side of them and say the predecessor: "I am your predecessor, 3,541."
- Then, move to the other side of them and say the successor: "I am your successor, 3,543."
You can switch roles and let your child be the predecessor and successor. This physical activity helps connect the words to the actions of "before" and "after".
Exploring the Boundaries
It's important to see what happens at the edges of the 4-digit number range. This is where the understanding of place value really helps. Let's look at two interesting questions:
- What is the predecessor of the smallest 4-digit number, 1000?
- What is the successor of the greatest 4-digit number, 9999?
The resource we used earlier has a great section that walks through these "important questions". Working through them will help solidify your child's understanding.
Successor and Predecessor of 4-Digit Numbers (Examples+Worksheet+Ans)
This section addresses important edge cases that build a deeper understanding.
Read through the four solved questions in this section. Pay close attention to how subtracting 1 from 1000 results in a 3-digit number (999) and adding 1 to 9999 results in a 5-digit number (10000).
Time for Practice
Now it's time to put this knowledge into action. The worksheet in our resource provides excellent practice for finding both successors and predecessors.
Successor and Predecessor of 4-Digit Numbers (Examples+Worksheet+Ans)
This worksheet allows your child to apply the rules and practice finding successors and predecessors for a variety of 4-digit numbers.
From the section "Worksheet on Successor and Predecessor of 4-Digit Number," please have your child attempt a few problems from each part. For example: I. Write the successors...: Try questions (i) 1473, (v) 2599, and (vii) 2079. II. Write the predecessors...: Try questions (i) 5015, (ii) 9000, and (xi) 2300. The answers are provided at the bottom, so you can check the work together.
Conclusion
That brings us to the end of our first day! We have covered a lot of ground, from place value and expanded form to today's lesson on predecessors and successors. Your child is now equipped with the fundamental tools to understand and work with 4-digit numbers.
Key Takeaways:
- The successor is the number that comes just after. It is found by adding 1 to the number.
- The predecessor is the number that comes just before. It is found by subtracting 1 from the number.
- The predecessor of 1000 is 999.
- The successor of 9999 is 10000.
In our next session, we will start Day 2 by using this knowledge to compare 4-digit numbers using symbols like greater than (>) and less than (<). Understanding a number's immediate neighbors is the very first step in being able to compare it to any other number. Well done today