You can teach children the basics of mathematics from the age of three to four. Usually, children of this age already know how to meaningfully calculate how much they see certain objects, and not just point fingers at them, calling numbers, as babies of two years do. The main thing is to conduct training so that it is feasible and brings pleasure to the child.
Start learning counting with real examples. When going for a walk, ask your child to count the number of animals he sees in the yard. Trees, houses, and the number of windows in them, and even swallows on wires, can also be good illustrative examples. Back home, count the number of boots in the hallway, and ask your baby how much it increased after you took off your shoes. You can ask to count the number of cutlery on the table. Have your toddler first count all the forks and spoons separately and then put them together.
When teaching children, especially small ones, one cannot but do without elements of the game. Take your child to an imaginary store, naming the pre-necessary products for you and their quantity. After that, accidentally "forget" about some product or name the wrong amount, so that the child will correct you. Thus, you will train not only his counting skills, but also develop memory. The “payment” process must also take place. Of course, for this purpose one should not use real money, but an invented "currency", for example, candy wrappers, buttons or sheets of colored paper. Give them to your child for the correct answers and the shown ingenuity.
To study the numbers from one to ten, use the pictures with these numbers, which you can buy or make yourself. The main thing is that they are beautiful, bright and always in front of the baby's eyes. Draw the child's attention to the number "zero". Explain to your child that this means "nothing".
After successfully studying, move on to the next step - studying dozens. It is best to explain the formation of such numbers on matches. First, lay out ten matches of one color, and on top - ten matches of a different color. Lay them out in order and name each number separately. Explain that two dozen is twenty, three dozen is thirty, and so on. Make sure that the child has successfully absorbed the information received, then teach him to add and calculate in the same way as in the previous stages.