National 5
FRACTIONS, DECIMALS AND PERCENTAGES
SUBJECTS STUDIED AT SCHOOL
FURTHER EDUCATION:
Mechanical engineering (3 years completed, 4th year in progress)
Maths
Physics
French
MEET SHIV
RDD Intern, Dyson
CAREER JOURNEY SO FAR
Placement year at Leonardo MW
Summer Internship at Dyson
Further Maths
FUTURE ASPIRATIONS
I am looking to secure a graduate job as a mechanical design engineer.
Q&A WITH SHIV
What does your company/organisation do?
Dyson makes domestic products such as vacuum cleaners, haircare products and air purifiers. It also is looking to expand its business, by moving into new product ranges.
What types of activities do you do in your job?

Develop concepts for a product
Brainstorm
Sketch ideas for a product

Develop computer models of the concepts

Prototype and test the concepts
What does a typical day at work look like for you?

0800 – 09:59  Finalise a computer model for a concept and send it off to be prototyped using 3D printing.

10:00  11:59  Brainstorm new ideas for a product in a meetings.

12:00  12:30  Lunch

12:30  2:30  Collect the parts that have been prototyped and assemble them. Also plan out a way to test the prototype.

2:31 4:30 – Test the prototype and evaluate whether the product works well. Then take those observations to make a better product.
What are your favourite things about your job?

Being able to make a physical product.

Being able to have a variety of working environments, e.g. working in labs and in an office.

Being able to learn something new everyday and use it to make better products.
HOW SHIV USES FRACTIONS, DECIMALS AND PERCENTAGES AT WORK

To plan projects using tools such as Gantt charts

Make design calculations

To analyse and collect testing data for a new products
ACTIVITIES
Problem 1
A rectangular plate as seen in the image below, has a width of 50mm and a length of 90mm. Six holes need to be drilled in the plate whilst being equally spaced and using the full area of the plate. Use fraction multiplication to find the required spacing between the holes.
Hint: the holes can be in either a 2 by 3 arrangement or a 1 by 5 arrangement.
Problem 3
A new motor for a vacuum cleaner needs a new power of 1 and 4/5 Watts. The existing motor has a power of ¾ Watts. An engineer recommends adding a second motor of a power of 1 and 2/5 Watts to the existing motor, the new power will be the sum of the two motors.
Is the engineer correct?
Problem 2
New materials are often used in Dyson products. A coated plastic material, Material A, is used which has two layers, 12mm silicon and 125mm polycarbonate. What is the total thickness of Material A?
Another supplier has a material (B) with layer thicknesses of 34mm silicon and 115mm polycarbonate. What is the total thickness of Material B?
Which material is thicker A or B?
Problem 4
A tolerance is the amount of allowable variation between part designed by Dyson and the part produced after manufacture. The affect of multiple tolerances needs to be considered when design products. For a new vacuum cleaner the tolerances of 4 part need to be added together to check whether there is enough space in the machine. The amount of space available is 2mm.
The tolerances (in mm.) are as follows: ½, 1/3 ,1/4 and 7/8.
Is there enough space in the machine?