This DIY lesson on Beginning Subtraction uses materials you probably have at your home. The lesson should be presented to a child who already understands the concept of numbers at least till ten and the concept of addition.
First, you need to make "Number-Jars" - see how below:
For your "Number-Jars" you can use spice jars, jam jars or any other shallow dish for each number (lids are not necessary). So, for example, the "Number -4-Jar" must have the proper number of the following materials since the purpose of every Montessori lesson is to have a control of error:
- equations (see picture above) - so the "Number -4" Jar will have four equations (unless you would like to add an equation "minus zero"); you can use colored cardstock (buy here) and yourself write down the equations and then cut them out; we are using wooden Montessori equations (similar here); alternately you can use these wooden numbers to "make" an equation;
- separate answers for each equation;
- the same amount of marbles as that Number-Jar, so in "Number -4" Jar, you will have four marbles;
- a tray (buy here).
For numbers 1-jar and 2-jar, I am using shallow dishes since number "1-jar" will have just one equation with one answer and one marble, and number "2-jar" will have two equations, two answers and two marbles.
Adrian (3.5 years old) is working with the "Number-5-Jar."
The equations should be positioned on one side of the work and the answers on the other side.
What you will need for this lesson:
- two identical shallow bowls on the opposite sides;
- one different shallow bowl because you want to isolate what you are taking away - you want the "subtraction bowl" to feel very different to your child;
- Number-Jars which must contain the proper number of equations, answers and marbles;
- the sign "minus" meaning the subtraction/what you are taking away;
- "equal" sing - the result, what you are left with;
- a spare different bowl, which will contain the initial total number of marbles from that "Number-Jar."
This lesson is very concrete, and it is not merely memorization. It is very important to show a child how to recount each marble one by one and reiterate every part of the equation since at some point children will be working with large numbers. And, by showing a child each step over and over again, you are creating a solid foundation for the lesson, so that when children work on the lessons independently, if they make an error or if they do not have the right number of marbles, they will be able to go back and correct the process because they will remember that they have to count all the marbles in the first place.
If the child is comfortable and wants to do more, s/he can write down (copy) the equation solved. It is by no means required or necessary, but if your child has an inclination, let them write the equation and the answer down to show that they have completed this particular Number-Jar. "Mommy, I am on to the Number-7-Jar!" will be a proud exclamation you would hear from your child. See here a video of Adrian writing down the solved equation on his work-sheet. Also, see in this post a video of Adrian actually solving the equation "➕Addition Strip Board 🎥 Math Lesson".