Reverse Percentages
The below QuickQuestion Interface © generates random questions on finding the original amount after a given increase or decrease by a percentage.
Choose which type of percentages you want to use (NonCalculator percentages are 1%, 5%, 10%, 20%, 25%, 50%, 75%).
Then decide if you want to have questions where the amount has been increased, decreased or a mixture of both by choosing Random.
Finally, by setting Multiplier to yes, you will be asked for the multiplier needed for the calculation, rather than the actual original amount.
There is a 10QQI version of this activity.
Choose which type of percentages you want to use (NonCalculator percentages are 1%, 5%, 10%, 20%, 25%, 50%, 75%).
Then decide if you want to have questions where the amount has been increased, decreased or a mixture of both by choosing Random.
Finally, by setting Multiplier to yes, you will be asked for the multiplier needed for the calculation, rather than the actual original amount.
There is a 10QQI version of this activity.
Ideas for Teachers
The QQI activities are a great way to get all students working. Put random questions on the board, and then get students to answer them on miniwhiteboards. Once all students have answered, and held up their solutions (with working), reveal the answer to see if they were right. Discuss any misconceptions from the working they have shown, or if they have all got it correct, move on to another question (changing the options to make if more difficult if necessary).
The QQI activities are a great way to get all students working. Put random questions on the board, and then get students to answer them on miniwhiteboards. Once all students have answered, and held up their solutions (with working), reveal the answer to see if they were right. Discuss any misconceptions from the working they have shown, or if they have all got it correct, move on to another question (changing the options to make if more difficult if necessary).
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