Every day, we are faced with the challenge of comparing two quantities. It could be height, weight, salary, grade, and so on. If two quantities are to be compared, their units need to be the same.
Comparing quantities refers to a quantitative relationship between two quantities that reflects their relative size. This is simply a method for comparing the quantities.
It is possible to compare quantities using a number of approaches, including percentages, ratios, profits and losses, and simple interest.
Two quantities in the same kind and unit have a proportional relationship when one quantity is fractionally a part of the other.
The ratio a:b is the same as the fraction ab, and it is written as a:b.
When a : b are equal, we call the antecedent and b the consequent.
It is essential that the units of two quantities be the same.
The four quantities are called proportional when the two ratios are equal.
The equation a : b :: c : d can be expressed as a : b : c : d.
Percentages can be obtained by multiplying fractions by 100 and adding a % sign
As an example, 14 = 14 × 100 = 25%
Learning Videos for 7th Grade Math - Comparing Quantities
Jameek rented a moving van for one day at a rate of $30 per day plus $0.25 per mile. Which of the following equations can he use to calculate c, the cost, in dollars, of renting the van for one day and driving it m miles?
A. c = 55m
B. c = 30.25m
C. c = 30 + 0.25m
D. c = 0.25 + 30m
Question 2
A clothing shop has a markup of 45% on the wholesale price of shirts. If the wholesale price of men's shirts is $35.00, what will be the retail price?
A. $80.00
B. $52.50
C. $57.50
D. $50.75
Question 3
Sam needs to buy 15 screws and 23 nails. Which of these equations would represent Sam's situation if the nails cost $0.59/nail and the screws cost $0.42/screw, and x represents the total cost?
A. 15(0.42)+23(0.59)=x
B. 15(0.42)xx 0.59=23x
C. 0.42/15+0.59/23=x
D. 15/0.42+23/0.59=x
Question 4
A regular item costs $8.50 and there is a discount of 45%. What is the amount discounted?
A. $3.83
B. $4.67
C. $4.83
D. $3.67
Question 5
In math class there are 15 girls and 5 boys. Which comparison statement is not an accurate statement?