Working Memory in Children: What It Is and How to Boost It with Games

Your child starts a sum and halfway through asks, "Where was I?" You give three instructions and only the first one gets done. They reach the end of a sentence and have forgotten how it started. This is often put down to carelessness or laziness, but the cause may lie elsewhere — in working memory. In this article we explain in plain language what working memory is, why it matters, and how to train it at home and through games.

What is working memory?

Working memory is the brain's "desk". It is where we hold the information we need right now for a few seconds and do something with it: remembering a phone number until we write it down, keeping an in-between result during a mental sum, holding on to a teacher's instruction while carrying it out.

Unlike long-term memory, this desk is small. Only a little fits on it at once, and when something new arrives, something old falls off. Adults have a limited desk too, and in children it gradually grows with age. That is why a seven-year-old and a twelve-year-old cannot be measured by the same yardstick.

Why working memory matters for maths, reading and following instructions

• Maths. To work out 47 + 38 in their head, a child has to hold the sum of the ones while adding the tens. In a multi-step word problem they must keep the question, an in-between answer and the next step in mind all at once.
• Reading. Remembering what the start of a sentence meant by the time you reach its end is the basis of understanding text.
• Following instructions. "Open your book, find page 25, do exercise 3" is a chain of three links. Without enough working memory, the chain snaps in the middle.

Working memory is closely tied to attention: a distraction literally sweeps everything off the desk. We cover attention in detail in how to improve a child's concentration.

Signs of weak working memory

If these situations come up often, working memory is worth a closer look:

• only part of a multi-step task gets done;
• in mental arithmetic the child loses track exactly where they need to "carry the ten";
• when copying, they keep looking back at the board and skip words or numbers;
• they know how to solve it but get muddled in a long problem — some careless mistakes come from exactly here;
• they seem to "switch off" during long instructions.

These signs are not a diagnosis: they can come from tiredness, too little sleep or simply age. If something really worries you, talk to the teacher or a specialist.

Screen-free games at home

• "I went to the market". Each player adds one item to the list and repeats the whole list from the start: "apple", "apple, bread", "apple, bread, carrot"...
• Numbers backwards. Say 3–4 digits; your child repeats them in reverse: "5-2-8" → "8-2-5". If it is easy, add one more digit.
• What's missing? Put 6–8 objects on the table, let your child look for 20 seconds and close their eyes, then remove one. Which one is gone?
• Chain commands. "Pick up the red pencil, walk to the window, clap twice for me" — add steps gradually.
• Car maths. "Start with 7, add 5, take away 3, double it" — the answer only at the end.

You will find more ideas in our article on memory games for children.

How N-Back, Digit Span and Simon train it

MentalMath's brain games have a "Working memory" category with 14 games. Three of them are a good place to start:

• N-Back. Digits appear on the screen one at a time. If the current digit matches the one shown N steps earlier, the child presses "MATCH". In 1-Back they only need the previous digit; in 3-Back they need the one from three steps back, while the contents of the desk keep updating with every new digit.
• Digit Span. Digits are shown one by one, then typed in order. The chain gets longer level by level, and on the hard level the digits must be typed in reverse. The child's result is compared with the average for their age.
• Simon (colors). Colours light up one after another with a sound, and the child presses them in the same order. The sequence starts at 3 colours, grows by one after a correct answer and shrinks after a mistake — so the child always practises right at the edge of what they can do.

Mental arithmetic uses working memory too: holding the image of the soroban and the in-between results happens on that same desk.

Realistic expectations: what games do and don't do

Scores in the trained game usually climb quickly, which is great for motivation. But to be honest: progress in a game does not automatically turn into better school marks. Researchers still debate how strong this "transfer" really is. Games work best alongside real skills — mental arithmetic, reading, completing multi-step tasks independently. So treat brain games not as a "cure" but as one part of the daily routine.

How much practice per day

Short, regular practice beats long, occasional sessions. A rough guide:

• ages 6–8: 5–10 minutes a day, 1–2 games;
• ages 9–12: 10–15 minutes, 2–3 games;
• 13 and older: 15–20 minutes.

Five days a week is plenty. If your child is tired or irritable, keep that day's session shorter. For fitting lessons, practice and rest together, see our article on a daily routine with mental arithmetic and brain games.

Where to start with MentalMath

It helps to first find out where your child is strong and where they need support. The baseline assessment is 6 short games taking 5–7 minutes, and it gives you a cognitive profile with strengths and weaker areas. After that you can start the Brain Plan — a focused 14-day plan with short daily sessions, plus a summary sent to you on Telegram on day 7 and day 14.