Here is my translation of chapter 8 from Sukhomlynsky’s book, 100 Pieces of Advice for Teachers:

8. Committing elementary knowledge to long-term memory
Thirty years of working in schools has led me to uncover an important secret, an educational principle. The students who fall behind in middle and senior school are those who in primary school did not commit to long term memory those elementary truths that form a basis for all knowledge. Imagine that the foundation for a tall building is laid on very unstable concrete. The mortar keeps crumbling and stones keep falling out. People continually have to repair what was not done properly in the first place, and live in constant fear of the building collapsing. This is the situation that many language and mathematics teachers find themselves in when teaching grades four to ten. They are trying to construct the building, but the foundation is crumbling.
Teachers in primary schools! Your most important task is to build a strong foundation for knowledge: so strong, that the teachers working after you do not need to think about that foundation. If you are commencing work with grade one, study the grade four program, mainly in language and mathematics, and have a look also at the grade five program in mathematics. In your class reader, compare the reading material on history, science and geography with the grade four programs in these subjects. Think about what a student needs to learn in grade three in order to study successfully in grades four and five.
Most importantly, think about elementary literacy. In our language there are roughly 2,000–2,500 spelling words that provide a framework for knowledge and literacy. Experience shows that if children firmly commit these words to long term memory, they will become literate adults. But that is not the whole story. If literacy is acquired in primary school, it becomes an instrument for acquiring knowledge in the middle and senior classes.
When teaching children in the primary school I always had this list of important spelling words in mind. That list in itself provides a program for elementary literacy. I distributed those two and a half thousand words in such a way that we studied three words on each school day. The children recorded them in their exercise books and memorised them. This work takes a few minutes each day. Young children’s memories are very sharp and versatile, and if you manage those memories well and do not overload them, they will become your best helpers. What a student memorises during the early years is never forgotten. The ‘technique for managing memory’ in this case consists of the following. At the beginning of the working day (before the first lesson) I write the three words for the day on the board, for example: steppe, warmth, rustle. As soon as they enter the classroom, the children write these three words in their spelling dictionaries, which they maintain for three years. They think about these words, and next to them write several words with the same root. This only takes three or four minutes, and the students gradually get used to this routine.
The work then takes on some of the characteristics of a game, incorporating elements of self-education and self-assessment. ‘On the way home,’ I say to the children, ‘Remember the three words we wrote this morning, and how they are spelt. Recall the outline of these words. In the morning when you wake up, the first thing I want you to do is remember the spelling of these words and write them in your exercise book.’ (The exercise book in question is a general exercise book that amounts to a second copy of their spelling dictionary.) There is no student who will not join in this game if you begin it in grade one, if teachers believe in its success, if they love children, and if they are always interested in everything the children do. During lessons at school a great variety of activities are conducted to ensure that the spelling words that have already been memorised are revised and put to use. One of the most important activities I conduct is to memorise 400 turns of phrase, which I am convinced provide a framework for oral language. During the primary years special attention is given to those turns of phrase that are commonly misused.
I would like to emphasise once more that it is very important to introduce an element of play into children’s studies. I have a list of 600 ‘fairy-tale’ words that are often used in children’s fairy tales. During the four years of primary schooling the children and I draw several dozen fairy-tales. The children write captions to these illustrations, using the 600 words. This has proved to be a very successful way of reinforcing basic spelling words.
When studying mathematics in the primary school, children memorise those operations that, due to their frequent repetition, may be considered mathematical generalizations. They are so habitual that it is meaningless to waste effort thinking about them each time they are required. I am speaking not only of the multiplication tables, but also of the most common instances of addition, subtraction, division and multiplication involving numbers up to one thousand. Children also memorise the most common measurements and conversions of measurements. I work on the principle that in the middle and upper grades students’ intellects should not be occupied with basic operations, but should be free to engage in creative work.
Of course all our work is based on conscious mastery of material, but at the same time we should recognise that it is not possible to explain everything. I aim for a combination of voluntary and involuntary attention and memorisation.
[Translator’s note: By ‘involuntary’ attention and memorisation Sukhomlinsky is referring to that which arises through spontaneous interest and engagement. He has commented elsewhere that when working with children in the early years, it is essential to engage their interest spontaneously through engaging content, as young children are for the most part incapable of forcing themselves to pay attention.]