You will need to know how to perform operations on whole numbers for your test.
Whole numbers are positive and negative integers that do not contain decimals or fractions.
Operations on whole numbers will be covered indirectly on a number of question types on your math test.
For example, you will have to add and divide whole numbers in order to calculate averages.
You will need to know how to round whole numbers in order to do estimating problems.
Knowledge of whole numbers is useful for doing shortcut operations on mixed numbers, which are numbers that contain a whole number as well as a fraction.
Understanding basic operations on whole numbers is also needed for the calculation of percentages, measurements, algebraic equations, and practical problems.
Multiplying Whole Numbers
(1) Sonya is painting the rooms in her house. If each room takes 3 buckets of paint and she has 8 rooms to paint, how many buckets of paint will she need in total?
A. 8
B. 11
C. 16
D. 24
E. 28
Solution: Multiply the factors together to get your result.
3 buckets per room × 8 rooms to paint = 24 buckets of paint needed
So, the correct answer is D.
Dividing Whole Numbers
(2) Keiko eats a bag of noodles every 6 days. Approximately how many bags of noodles will she need for one month?
A. 5
B. 6
C. 7
D. 8
E. Cannot be determined
Solution: For ease of doing the calculation, we can assume that the month has 30 days.
30 days ÷ 6 days per bag = 5 bags of noodles
So, the correct answer is A.
Many students would find problems like the two above quite easy to complete.
However, problems involving both the division and multiplication of whole numbers are often more difficult for many students.
It is quite likely that you will see math problems on your test that require multiple operations. In other words, one problem will often involve both the multiplication and division of whole numbers.
Multiple Operations on Whole Numbers
(3) Juan has a large dog that eats 10 cans of dog food every 2 days. Approximately how many cans of dog food will Juan need to feed his dog per month?
A. 60
B. 100
C. 150
D. 200
E. 300
Solution: Remember that you can assume that the month has 30 days because the problem uses the word “approximately.”
STEP 1: Divide the number of days in the month by the number of days of the consumption rate.
30 days in the month ÷ 2 day consumption rate = 15 days
STEP 2: Multiply the result from step 1 by the quantity consumed.
15 days × 10 cans = 150 cans
So, the correct answer is C.
You should now have a look at the free material on positive and negative integers.