4th grade / Multiply + Divide / Best Price / Dividing by 10
The first question in this topic is as follows. If marbles cost 10 cents each, but a packet of 10 costs 90 cents, what is the amount you save PER ITEM by buying the packet.
So, if a packet of 10 marbles costs 90 cents then each marble in the packet costs:
90 ¢ ÷ 10 = 9 ¢ per marble
Which compares to 10 ¢ if we buy them individually.
So in this case the saving PER ITEM is:
10 ¢ - 9 ¢ = 1 ¢ per item
If you are finding this difficult, you might like to work through the lesson Introduction and Either / or activities before tackling the games.
With these interactive math lessons you will be learning "Dividing by 10" from
4th grade / Multiply + Divide in 3 easy steps. The math in our lessons consists of 6 questions that ask you to use division by 10 to work out the best value for money item.
Price list | |
---|---|
Single sweet | 10¢ |
Packet of 10 sweets | 90¢ |
Price list | |
---|---|
Single sweet | 20¢ |
Packet of 10 sweets | $1.80 |
Price list | |
---|---|
Chocolate bar | 50¢ |
Packet of 10 | $4 |
Price list | |
---|---|
Pencil | 30¢ |
Packet of 10 pencils | $2.50 |
Price list | |
---|---|
Single pen | 60¢ |
Packet of 10 pens | $6.00 |
Price list | |
---|---|
Single pen | 60¢ |
Packet of 10 pens | $4.00 |
In these math topics, we explore division by working out what the price per item is if you buy a whole pack or other group container like a box or a book (of stamps). Often retailers will price a group of items in a box or packet at less per item in order to sell a greater quantity of items.
For instance, buying individual marbles might cost 10 ¢ each, but buying a packet of 10 marbles might cost say 80 ¢. In this case, you can probably see immediately that the pack price is "better" than the individual price, but how can we work out what the acutal saving is? There are 2 simple ways to work out the saving: either multiplying the individual item price by the number of items sold in the packet, or dividing the packet price by the number of items in the packet. If we do the latter we find that the price of each marble in the packet is
80 ¢ ÷ 10 = 8 ¢
Which compares to 10 ¢ if we buy the marbles individually. So in this case the saving ** per item ** (which is what these topics are about) is:
10 ¢ - 8 ¢ = 2 ¢
Next time you are in a shop where you can choose to buy a packet or individual items, see if you can figure out what the saving is... it could save you a packet!
There are 3 easy math lesson activities in this "Dividing by 10" tutorial. These activities progress step by step to help you the learner gradually master this math topic. The activities are based on "3 stage questioning", a method of learning that quickly and easily builds your confidence as you work through the short series of lessons that strengthen your knowledge of the math that you want to learn.
When you have completed the tutorial for a topic, you should try some of our games before finally doing the test for your chosen topic. See the Help box below for detailed instructions on how to use the lesson activities to help you learn your math more easily.
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Rock fall * Four in a row * Sow grow * Choose or lose * Mix and match
You start the tutorial with a lesson that introduces the math you will be learning. You will see a set of questions one at a time, and for each question you will see the written answer and also hear the answer to that question.
Repeat the question/answer by clicking on the brown speaker sign. Repeat the question/answer and expand the question graphic by clicking on the question box. Move between questions using the arrow buttons below the question. If there is additional information available for your chosen topic, the "i" button on the left upright bar will be brown on white. Click on the button to load the additional lesson information into the main interface.
This lesson moves on from the "Introduction" lesson and offers you two possible answers to each question. So, you will see a question then a voice will ask "Is this ... or is it ..." and you will have to choose which of the answers is the one that matches the question.
You choose an answer by clicking or tapping on one of the two answer boxes below the question. You can play the audio for each answer again by clicking on the speaker icon beside the written answer (if robot speech is available and enabled). The program will let you know each time whether you answered correctly. A star will light up red for a wrong answer or white/black for a correct answer.
This lesson asks you the questions in a random order compared to the introduction. At the end of the lesson, you can choose whether to repeat the lesson or move on to the next one.
The final lesson of the tutorial shows you multiple possible answers for each question - you must choose the correct one. You are asked a question and below it are a list of two, three, or four possible written/numeric answers from this topic. Pressing the speaker icon will play the math audio for that answer.
For each picture, click on the answer that matches the question. The program will tell you whether you are right or not. As with the Either / Or activity a system of stars indicate your right and wrong answers. The What is it? lesson will show you all the questions you learned in the Introduction but in a random order.
When you complete the "What is it?" lesson, you can choose whether to go on to play some games with this topic, or whether you want to repeat some or all of the lesson activities in this tutorial. You should expect to get 80% of the answers correct in most of the activities before trying some of the Math games with this topic.
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