construction
Fraction to decimal
A drawing labels a length as 3/8 inch. What is this in decimal inches?
See the worked explanation
Divide the numerator by the denominator: 3 ÷ 8 = 0.375 inch.
Practice at your own pace
Make the numbers familiar
Try a foundation exercise, check your reasoning and explore the worked explanation. These are learning examples, not workplace instructions or an admission test.
construction
Rectangular area
A rectangular surface is 12 feet long and 8 feet wide. What is its area?
See the worked explanation
Area = length × width = 12 × 8 = 96 square feet. Area units are squared.
manufacturing
Add measured lengths
Three practice pieces measure 125 mm, 80 mm and 45 mm. What is their combined length before any cutting allowance?
See the worked explanation
All measurements share the same unit: 125 + 80 + 45 = 250 mm.
manufacturing
Read a tolerance range
A classroom drawing specifies 20.0 mm ± 0.2 mm. What is the largest dimension in that stated range?
See the worked explanation
Upper limit = nominal dimension + tolerance = 20.0 + 0.2 = 20.2 mm. The lower limit is 19.8 mm.
transportation
Convert a length
For a measurement exercise, convert 2.5 metres into centimetres.
See the worked explanation
There are 100 centimetres in a metre: 2.5 × 100 = 250 cm.
transportation
Training hours
You attend 4.5 hours of supervised instruction on each of 4 days. How many instruction hours is that?
See the worked explanation
4.5 × 4 = 18 hours. Breaks or travel are not included unless the stated timetable includes them.
energy
Power and energy
In a simplified classroom model, a 2 kW device runs at constant power for 3 hours. How much energy is used?
See the worked explanation
Energy = power × time = 2 kW × 3 h = 6 kWh. This model assumes constant power.
energy
A percentage of a quantity
A diagram contains 80 identical units. If 25% are highlighted, how many are highlighted?
See the worked explanation
25% = 0.25. Multiply 80 × 0.25 = 20 units.
healthcare
Metric volume conversion
For a unit-conversion exercise only, how many millilitres are in 1.2 litres?
See the worked explanation
1 litre = 1,000 millilitres, so 1.2 × 1,000 = 1,200 mL. This is not a medication or clinical calculation.
healthcare
Read a timetable
A classroom session starts at 09:15 and ends at 11:45 with no break. How many minutes long is it?
See the worked explanation
Two hours and thirty minutes = (2 × 60) + 30 = 150 minutes.
beauty
Stock cost per item
A practice budget contains 12 identical items costing $48 total. What is the cost per item?
See the worked explanation
Unit cost = total cost ÷ quantity = 48 ÷ 12 = $4.
beauty
Compare a kit discount
A kit has a listed price of $200 and a 15% discount. What is the price after the discount, before tax?
See the worked explanation
Discount = 200 × 0.15 = $30. Subtract it from $200 to get $170.
culinary
Scale a recipe
A classroom recipe for 4 portions uses 300 g of flour. At the same ratio, how much flour is needed for 10 portions?
See the worked explanation
Scale factor = 10 ÷ 4 = 2.5. Multiply 300 g × 2.5 = 750 g.
culinary
Calculate a yield
A practice batch starts at 2,000 g and has a usable yield of 80%. What usable mass remains?
See the worked explanation
2,000 × 0.80 = 1,600 g. The remaining 400 g is outside the usable yield in this example.
technology
Distinguish binary storage units
Using binary units, 1 GiB equals 1,024 MiB. How many MiB are in 4 GiB?
See the worked explanation
4 × 1,024 = 4,096 MiB. GiB/MiB are binary units; GB/MB commonly use decimal units.
technology
Average a measurement
Three practice measurements are 12, 15 and 18 milliseconds. What is their arithmetic mean?
See the worked explanation
Add the values and divide by the count: (12 + 15 + 18) ÷ 3 = 15 milliseconds.
Build the foundation further
If a calculation feels unfamiliar, revisit the units and the operation before trying again. OpenStax’s free Prealgebra text offers further study. Our exercises are original examples; no answers are submitted or stored.
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