Remember and Recall Numbers

By: Camrin Wong and Marc Webb


This experiment was to test how well teenagers the ages of 14-16 could memorize digit sequences so it could lead to helping them in the real world with things such as phone numbers. People nowadays just quickly insert phone numbers onto their contacts without thinking what if they all got erased or if they needed one important number but never cared to remember it. The memorization tests uses a series of 2-10 digit sequences to see how many numbers an individual is able to get correct out of the maximum possible. Question at hand during the experiment was which age from the age group of 14-16 could be able to remember the most numbers within a given time period. We predicted that the 16 year olds would be able to remember the best due to maturity and experience. Using several spreadsheets and graphs when all data was obtained, we created multiple averages for all ages and averaged how many numbers they got correct out of 9 numbers, out of 10 numbers, and the maximum amount an individual received within each age. After trials were done, we averaged our results to find out that 14 year olds remembered 7.31 numbers correctly.Then the average amount of numbers that 15 year olds remembered correctly was 7.3 and 16 year olds remembered 7.5 numbers correctly. That shows that the oldest age which is 16 was able to remember more numbers correctly on average.

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Problem- Which age from the age group of 14-16 will be able to memorize and repeat number sequences in the most correct fashion?

Hypothesis- If someone from the age of 14 is shown a sequence of numbers and the same sequence is shown to someone the age of 15 or 16 then the 16 year old will be able to remember and recall the sequence back in the correct order more likely than the ages of 14 and 15 because since the tester is older, they are usually more mature and more likely to focus.

Parts of the Experiment

Independent variable

  • Amount of numbers people have to remember

Dependent variable

  • Number of correct answers from the participants. (Dependent because the more numbers, the less amount of correct answers and vice versa)

Control group

  • No control group is in experiment as everyone is applied the variable

Experimental Group

  • Everyone who is tested because they all got the variable


  • The numbers we show people (the sequences will stay the same)

  • How slow we read the numbers and how much time they have to respond

  • The age of people who participate (14-16)


  • 1 Computer with access to the internet for graphing purposes

  • *Optional* Have a shoebox or a rubber band to keep the notecards neat

  • 9 index cards (one for each set of numbers)

  • Either 2-3 sheets of paper depending on what how many people will be tested with a table or an electronic version


  1. During this experiment, you will need a variety of number sequences for individuals to memorize and for them to repeat back. Each sequence should be made up of numbers 0-9 and the size of the sequence must be starting from 2. Each sequence increases by one each time so it starts from 2,3,4,etc up to 10. Even if the participant isn’t able to remember the set amount of numbers for example 7, move on to the next sequence which would be 8 digits long. You can personally come up with the sequence use a random number generator to help you create different sequences.As you create the cards, use the same ones for every participant so results are more accurate.

  2. Then retrieve your index cards and begin coming up with digit sequences or copy them off of the generator used if available.

  3. Begin by writing two numbers on an index card and label the card 2 so you know that card has a number sequence of two numbers.

  4. Repeat step 3 for each digit sequence greater than 2 starting from 3 and ending at 10. You need to write the needed amount of random numbers for each card and label the card according to the amount of numbers on that card.

  5. After writing the cards, you should have 9 cards that have different digit sequences on them and different amount of numbers. These will be read aloud to the participant during experimentation and participant will be asked to repeat them back. The speed in which you read the sequences should remain constant as well and not to speed up or slow down. Pick participants within certain age groups such as 13-15 so results are more accurate as well.

  6. A data table is needed with a place to record the highest number of correct answers for each volunteer and have a separate box for each set of numbers starting from 2 and ending at 10.

  7. During experimentation, explain to the participant that you will read a series of numbers to them slowly, and then after hearing the number sequence you want them to repeat the same numbers back in the same order that you read to them.

  8. Take notes on the table on how many numbers the participant was able to get correct out of the digit sequence.

  9. Make a table/graph to analyze the data in the end such as a histogram and label the graph/table accordingly to the question at hand.

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  • Very few people are able to remember a 10 digit sequence and being able to recall it.

  • When reading numbers to the participants and having them repeat the sequence back, they usually ended up scoring more correct answers if numbers are sequential such as triple 5s, 1-2-3, 9-8-7.

  • 100% of the participants who were tested could repeat at least 5 digits without making an error during their trial.

  • Some seemed off task or fidgeted around during trials which could have affected our results.

  • Non-sequential numbers gave those a harder time repeating the same sequences we read to them because they could’ve tried to focus an area of the sequence, but didn’t focus on the other like 8-2-6-7-1-5-3 as all of those numbers aren’t directly next to each other.

Calculations/Stat Analysis

There weren’t very many calculations made as the spreadsheet was able to configure the results due to our data. We received 1.38 as our standard deviation for 14 and 16 year olds and 1.24 as our deviation for 15 year olds. The average of the most correct numbers the participant got right would be 7.31 for those the age of 14, 7.33 for 15 year olds, and finally 7.5 for 16 year olds. To calculate standard deviation and our averages, we entered in all of our data into a spreadsheet and used “=AVERAGE(data set here)” for the spreadsheet to figure out all of our averages from participants. As for standard deviation we typed in “=STDEV(data set here)” and it calculated the deviation between our results and that was done for all ages 14-16.

Statistical Analysis-

Standard deviation is shown in the Z-Test as the variety of correct answers and the norm of the differences between them. They tell us how much the results varied from each person in each age group and there were also averages which showed us the average number of maximum correct answers out of each age group as well. We created a null hypothesis that there would be marginal-little difference between the averages of correct answers between age groups. The usual 0.05 is used to discuss the hypothesis. We received 0.69 as our Z-Test hypothesis and if the decimal is above 0.05 then our hypothesis is correct, and if under it is not. The average of the averages of maximum of correct answers out of all age groups was 7.38. That means that out of all ages, the average of maximum correct answers is 7.38.

CER Analysis

During the experiment, one trend stood out the most to us and it was that most of our participants were able to repeat sequences back to us more fluently if numbers were in day-day order. What that means is that in our digit sequences that contained series of numbers such as 1-2-3, 5-5-5, 9-8-7 and other numbers, the participant was able to fluently repeat that part without having to stop for a quick second to contemplate on what the next number is.

Out of our plethora of trials, we received 3 different averages in total out of 3 ages (14,15,16). The average of the maximum amount of numbers someone the age of 14 could repeat back to us was 7.31. The average of the maximum digit span of a 15 year old was 7.33 and finally 7.5 for 16 year olds. Now the maximum number is what we got from how many numbers they could remember the most out of any trial so if they remember 9/9 but only 8/10 or 6/8, then we used the 9/9 because that was their most correct trial. Those averages are only that high because some of the digit sequences contained those repeated numbers or those we see on a daily basis (1-2-3, 5-5-5, 6-7-8, etc). In our statistical analysis, we found out our standard deviation for 14 and 16 year olds was 1.38 and it was only 1.24 for 15 year olds. Those showed that there was about a 1.24-1.38 change in the maximum amount of numbers someone got right. The trend in the standard deviation shows that there were some high digit sequences people were able to remember (9+) and the deviation was only 1.24 for 15 y/o and 1.38 for 14 and 16 y/o which shows clumped data and that everyone was able to remember quite a good amount of numbers due to repetition in digits or day-to-day digit sequences.

These results were produced during the experiment due to the function of our human brain. Ever since we were born, our brain takes in what we witness whether that be noises, tastes, sight, sound, etc, and the more we hear, taste or witness those things, the brain creates a memory from them so if it occurs again, we know what it is. That relates with the repetition in sequences leading to increased numbers correct in our memory test. When growing up, we learn how to count starting from 1 and it continues from there. 1-2-3 is the most common sequence as its the first three whole numbers in existence and that is what everyone learns from childhood and since we were taught to remember those, no matter how old we grow those simple sequences like 1-2-3-, 7-8-9, etc won’t leave our memory. As long as those who pay attention to the sequences and know any number from 1-10, they will be able to repeat them in digit sequences because it is just one number like 4 and repeated however many times it is in the sequence. This test causes the brain to recall all of those simple sequences we learned in elementary school and applied them to the memorization test at hand.


Overall, the experiment was a success. Both the problem and hypothesis were proven correct by the data and trials. Our hypothesis stated that 16 year olds would remember digit sequences more correctly than 14 and 15 year olds. Our averages show that 16 year olds had an average of 7.5 numbers remembered and only 7.33 for 15 year olds and 7.31 for 14 year olds. The trend contributed to the high scoring memorizations for the teenagers. Since the 16 y/o are more mature (most likely) and experienced, they could apply themselves better towards the test rather than 14 or 15 y/o. Those repetition in digits such as 5-5-5 or those simple sequences like 1-2-3 were numbers no one could get incorrect considering the fact that the brain itself brought back all the times you’ve been able to recall those numbers.

Source of Inaccuracies

There were very few sources of error for our experiment, but those errors could have ruined the whole project. One of the main errors was the person being tested is being distracted/had something on their mind. Not having focused participants could’ve led to corrupt results, but most participants if not all seemed in check. One of the ways to fix the error is to turn whatever you wanted into a reward, so if you do well you get the reward. Another source of inaccuracy is that we should have tested a more variety of ages to get better and more accurate results. To fix this, instead of getting majority from one age than other two ages are split off, we could’ve settled on a set number of participants on each age such as 30 of 14 year olds, 30 of 15 year olds, and 30 of 16 year olds.


Our project applies to real life because when we tested someone on ten digits to remember (thats how long a phone number is) the 14, 15, and 16 year olds we tested, only 2 that we tested could have remembered the ten digit sequence right away. It is important to know this because it shows that only 3.8% of the people tested have a strong focused short memory span. It also shows that 96.2% of the 14,15, and 16 year olds may have a decent short-term memory span but not the greatest. You can use the results we have to show that some people remembered higher on 7 and got all 7, but when tested against ten digits only remembering 6 digits show our data shows that some people remember more when tested with less digits to remember. This shows that when people say “what’s your phone number” they have to program it into their phone.


We could’ve improved our data by having more variety of ages and having a set number of people for each age instead of having too many of one age and not enough of the other. Expansion of this experiment could be done by adding on more ages or it could instead relate to gender such as male and female which gives us a new view on memorization. As well as ages and genders we could do environment they were tested in to see if they were able to focus and repeat the sequences. Many of different variations could be done to expand this experiment and take it further.