This is a level 4 number link activity from the Figure It Out series. It relates to Stage 7 of the Number Framework.
A PDF of the student activity is included.
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solve proportion problems
FIO, Link, Number, Book Three, Kapa Haka Hāngi, page 17
In this activity, the students will be multiplying and dividing with decimals to find unknown quantities.
The students could use the problem-solving approach suggested in the notes for page 15 when working on his activity.
Encourage the students to estimate answers from the information they know. For example, feeding 30 adults requires 12 kilograms of potatoes, and so feeding 60 adults requires 24 kilograms (doubling). This means that feeding 50 adults requires a little less than 24 kilograms and for 70 adults you must add a little more.
This information will help the students as they work towards the correct answer.
To work out the specific amounts, the students need to recognise the relationship between the amount of food and the number of adults. They are given the amount of food for 30 adults. There are several ways they could find the amount of food needed for 50 or 70 adults. For example:
• They could divide the amount of food needed for 30 adults by 3 to find the amount of food they need for 10 adults. They can then multiply this new amount by 5 to find the food needed for 50 adults and by 7 to find the food needed for 70 adults. This will be straightforward for food amounts that are easily divided by 3 (potatoes, kamokamo, cabbage, and lamb). Other food amounts will be a little more complex. Eight kilograms (or 8 000 grams) of kùmara will become 2.6 kilograms for 10 people, 13.3 for 50 people, and 18.6 kilograms for 70 people.
• They could work out what they need to multiply the 30-adult amounts by to get 50-adult amounts:
So they multiply all the 30-adult amounts by 1.6 to get the 50-adult amounts. They use the same process to find the 70-adult amounts.
To work out the amount of chicken, the students need to apply some common sense when rounding. The chicken for 50 people rounds nicely to 11.7 kilograms. For 70 people, however, the actual figure is 163.3, which should be rounded up to 163.4 so that there is slightly more chicken available rather than slightly less.
Answers to Activity
1. a.–b. (Figures are rounded to 1 d.p.)
2. a. Answers will vary.
b. Answers will vary.