What is a half?
First, let’s start with what half means. A half is two equal parts of one whole.
This is easier to understand when talking about halving shapes or real-life objects. For example, let’s imagine you have a whole pizza. To cut your pizza into halves, you must cut it into two equal pieces. Each piece is one-half of the pizza.
Finding half of an amount
We can use this concept to find half of an amount. Another way to think about halving is sharing equally between 2 people. An easy way to understand how to do this is by using physical materials you can touch, pick up and move around. For example:
Can you share four cubes equally between 2 people?
This is the same as finding half of 4 and is an easier way to learn how to halve numbers. Using physical cubes, you can share them between two people by giving one cube to each person until you run out of cubes. Count how many each person has, and there’s your answer!
You can do this with several objects lying around the house or classroom to practice halving. For example, why not use counters, books, pencils, or even yummy sweets? Remember, to halve means to share equally between 2.
Moving on from using physical manipulatives, you can use a whiteboard or pencil and paper to calculate half. Do you want to find half of the 12 bananas? Then draw out two circles to represent the two groups, and draw one banana inside each ring until you have none left. How many bananas are in each group?
How to halve numbers:
Half is the same as the fraction ½. This means that to find half of a number; we can divide it by 2. To divide by 2, split the total number into two equal parts. For example:
To calculate half of 6, we can divide it by 2. We can write this calculation as six ÷ 2.
This calculation gives us the answer 3. We can check this is the correct answer by adding it by itself (3+3) and making sure it is equal to 6, which it is. We can also check that our solution is correct by multiplying our answer by 2 (3 x 2), which equals 6. And there you go, you’ve learned how to halve numbers!
How to halve large numbers:
This is easier to do with smaller numbers, but when we try to calculate half of the large numbers, it can be tricky to divide the total number by 2. We can make this simpler by using partitioning. This is where we split the number into tens and ones to make it easier to halve.
Let’s take the number 86, for example. This would be tricky to halve quickly in our heads by diving by 2. So instead, split the number into tens and ones like this:
Half the tens first (half of 80), which is 40. Then, half the ones (half of 6), which is 3. Finally, add your two numbers together to get the answer. In this case, the answer would be 43!
You can also halve even more significant numbers using this partitioning strategy. Split the number into thousands, hundreds, tens, and ones, and calculate half using the same method above.
