Math Drills
Finding the Base Quantity
A-1Word Problems (Decimals, %)
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What this worksheet covers
- Topic
- Percentage
- Worksheet
- Finding the Base Quantity
The compared amount is divided by its percentage to trace back to the base amount. The percentage is shown as a decimal, as a percent, or as wari, and the wari questions restate it as a decimal before dividing. Where a question says an amount grew or shrank from the original, the word problems divide by 1 plus or 1 minus that percentage.
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A percent question needs one step before the dividing, turning the percent into a decimal. Divide by 40 with 40% left as it stands and the answer comes out a hundredth of the true figure, two places too small. What to multiply back by is the percentage itself in a basic question, or 1 with the percentage added or taken away in an increase or decrease question, and either returns the compared amount.
Of the three types, the direction that traces backward by dividing is complete here. From the next lesson a drawing expressing that percentage as a length or an angle gets read. The amount produced by multiplying in Finding the Compared Quantity has been moved here into the clues.
- Decimals (Basics)2 questions
- % (Basics)2 questions
- Decimals (Applying Increase and Decrease)1 question
- % (Applications)1 question
Questions & answers
Problems and answers on this worksheet
These are the problems in “Percentage”, shown with their answers.
(1)An amount equal to 0.3 of some water is 18L. What is the total amount of water in how many L? Answer □
Answer: 60L
(2)An amount equal to 0.3 of a milk carton is 90mL. What is the total amount of milk in the carton in how many mL? Answer □
Answer: 300mL
(3)Among the visitors to the event, the number of adults is 22 people, which is 55% of all the visitors. How many visitors were there in all? Answer □
Answer: 40people
(4)The number of red apples in the basket is 18, which is 30% of all the apples in the basket. How many apples are in the whole basket? Answer □
Answer: 60apples
(5)This month, 168 boxes were shipped, which is more than last month by a ratio of 0.4. How many boxes were shipped last month? Answer □
Answer: 120boxes
(6)The number of students at a school this year is 720 students, which is 10% fewer than last year. How many students were there last year? Answer □
Answer: 800students
What to do next
More worksheets in this unit
Finding the PercentageFinding the Percentage Word Problems (Decimals, Basic)
Finding the PercentageFinding the Percentage Word Problems (%, Application)
Finding the Compared QuantityFinding the Compared Quantity Word Problems (Basic)
Finding the Compared QuantityFinding the Compared Quantity Word Problems (Increase/Decrease, 2 Steps)
