K16
- Ivan and Helen have an equal number of coins. Ivan has 104 20-cent coins, and some 50-cent coins. Helen has 64 20-cent coins and some 50-cent coins. The total mass of Helen’s coins is 1.134kg.
a) Who has a higher value of coins? How much more money is the value of that person’s coins?
b) If each 50-cent coin weighs 2.7 grams more than a 20-cent coin, calculate the total mass of Ivan’s coins in kilograms. - can help me with this question?
- Hello!
- Let me try to draw a model to explain this question to you.
- Since Ivan and Helen have the same number of coins, I drew out this model. Are you able to understand?
- Yes, I get it
- I added more details to the model.
- Using the information given in the question, I broke down the model as such that there is an equal part of the model (for 50 cents) for both Ivan and Helen
- Similar to Helen, I also broken down Ivan’s model so that there is an equal part of 20 cents coins for the both of them
- It gets a little confusing. I will explain why I did it later.
- But for now, let me know if you are able to understand the model?
- i think so
- So both ivan and helen have this equal part of the model for 20 cents and 50 cents?
- Yes you are right. So we just have to compare the part that is different
- By comparing the model, we can tell that Helen has a higher value of coins.
- Yes, Helen has a higher value of coins.
- Can you try it yourself to show me how much more money did Helen have than Ivan?
- Ivan has 40 20-cent coins. Helen has 40 50-cent coins.
- 50 - 20 = 30.
30 x 40 = 1200 cents = $12? - Brilliant! That’s the correct answer
- Are you able to find out the answer for B as well?
- 40 x 2.7 = 108 g.
- 1.134 - 0.108 = 1.026 kg?
- Yup! You got it!
- Thank you so much!!
- The model helps me to understand the question.
- Goodbye
Session ended by student.
Adeline Lee, 
