Step 28: Multiply and Divide by 2
Connected concepts
In the previous learning step we discussed doubling. This is connected to a surprising number of related concepts, as you will soon see.
Multiplying by 2
Multiplying by 2 is the same as doubling. However, it uses interesting new wording that your child will need to get used to. When you first introduce the phrase of multiplying by 2, be sure to mix in the use of doubling from time to time to help with the transition. Your child will be getting used to the new words “multiplying” and “times.”
Half of something
When something is doubled, such as 3 doubled is 6, then you can take half of the result and get back the original number. For example, suppose you picture 3 doubled as two rows of 3 things. Then taking half of those two matched rows is to take one of the rows, which is 3 things.
Equal sharing
When you talk about taking half of something, you can combine that with the idea of sharing it equally among two people. If two people are to get equal shares, they will each get the same thing and that will be half of the original amount.
Dividing by 2
If your child is comfortable with all the concepts so far in this learning step, then they are ready to talk about dividing! You can start talking about dividing something equally, or dividing it in two, or dividing by two. Mix together using all these phrases with your child – it will take time for them to absorb this new vocabulary. As far as the math is concerned, they have mastered all the ideas already!
Concrete examples
Do lots of practice with each of these new ideas and words with groups of objects. Make your child’s understanding be concrete rather than simply abstract. Anytime there is something to share among two people is a perfect time to practice. You can of course start extending this to sharing among more than two people if you like.
The beginning of multiplying and dividing
As you have seen, this is the starting point of multiplying and dividing. There are one or two new ideas, and a lot of new vocabulary. It’s exciting to see your child step into this new part of the world!