1. Length Investigation
Aim:
To investigate the relationship between a person’s total finger length
and arm length.
Hypothesis:
We predict that Grade4 student’s arm length will be greater than their
total finger length.
Materials:
1 measuring tape
1 pencil
1 sheet of paper
1 clipboard
15 Grade4 students
Method:
1. Collect your materials.
2. Draw a table with 9 columns (name, 1st finger, 2nd finger, 3rd
finger, 4th finger, 5th finger, total finger length, arm length,
difference).
3. Ask someone to stretch out his or her fingers.
4. Put the 0cm of the measuring tape at the end of the person’s
1stfinger.
5. Pull the measuring tape up until it is in line with the bottom of
the finger.
6. Measure all other fingers.
7. Record the number of millimeters shown on the measuring tape.
This is the person’s finger length.
8. Add all the numbers of the finger length and record. This is the
person’s total finger length.
9. Ask the same person to stretch their arm straight and put 0cm on
their wrist.
10. Pull the measuring tape up until it is in line with the
shoulder.
11. Record the number of millimeters shown on the measuring
tape. This is the person’s arm length.
12. Repeat the measurements for the other 14 students.

2. Results:
1st 2nd 3rd 4th 5th Total Arm
Name finger finger finger finger finger finger length Difference
(mm) (mm) (mm) (mm) (mm) length (mm) (mm)
(mm)
HyunSeo 50 60 65 60 50 285 395 110
Diana 50 60 60 60 50 280 400 120
Kaopoon 50 63 70 60 55 298 395 197
Jermaine 55 65 70 63 55 310 460 150
Annie 45 58 65 57 45 270 390 120
NaYoun 50 60 65 60 50 285 400 115
Benidict 45 60 65 65 50 265 415 150
Jack 50 70 70 70 50 310 440 130
Sarthak 50 60 60 56 40 266 440 174
Kota 45 55 60 57 46 283 430 147
Hanson 50 55 60 57 50 260 455 195
Sajid 50 60 75 60 50 295 440 145
GeonWoo 50 60 65 60 50 385 375 10
Joshua 46 61 65 60 50 281 340 59
Kazuki 50 50 70 65 50 295 460 165
1 out of 15 people’s total finger length is greater than their arm length.
This is approximately 7% of the people measured.

3. 14 out of 15 people’s total finger length are smaller than their arm
length. This is approximately 93% of the people measured.
On average, people’s arm length was 13.18cm greater than their total
finger length.
Conclusion:
Our hypothesis was correct. We conclude that at 9-10 years of age, most
children’s arm length is greater than their total finger length.
Discussion:
Our sample size was only fifteen 9-10 years olds. They came from a
variety of backgrounds. We would need to measure more 9 year olds to
be sure of the percentage of difference between arm length and total
finger length. This would make our data more reliable.
We had some difficulties getting accurate measurements. Some people
didn’t measure in same way as others. We also didn’t start at the 0cm on
the tape and it was hard to keep measuring tape straight, which could
have made our measurements less accurate.
We would like to know people’s difference between arm length and
finger length changes at different ages and .It would be interesting thing
to measure different ages in different countries like babies, children,
teenagers and adults. This data can be more reliable.