Stage2-Brainwave5


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Brainwave 5

How Long is a Dollar?

Coins
There are different coin combinations which can be used to make the value of $1.
Find 5 different combination of coins to the value of $1. Place the coins side by side in a straight line and measure the length of each combination.

Coin combinations	Length

Which combination was the shortest and which combination was the longest?
Find a combination of coins to the value of $1 that is CLOSEST to 23cm long.

Feature Solution

The feature solution for the problem came from Year 4 from Tottenham Central School

What did you have to find out?
We had to find out 5 combinations of coins which adds up to one dollar.
We also had to find out which combination shortest, longest and which one was closest 23cm.

What materials did you use?
Coins, a pencil, rubber, brain power, paper money to stick our combinations into our books and a ruler.

How did you think? What strategies did you use? How did you solve this problem?
Step 1 - We started with the easiest coin combinations and worked our way up to the hardest. We recorded each combination in our books.
Step 2 - We measured the length of each coin combination.
Step 3 - We compared each combination to see which ones answered the questions.

What answers did you come up with?
Some of our many 1 Dollar combinations were: -
50c + 20c +20c +10c = $1
50c +50c = $1
(20c x 4) + ( 10c x 2)= $1
20c x 5 = $1
50c + 20c + 20c + 10c = $1
The shortest - 2 x 50c
The longest - 20 x 5c
23cm combination (4 x 5c)+ (4 x 10c) +(2 x 20c) = $1

Commendable contributors to the problem were:
Rachel & Nicola from Barham Public School
Woonona East Public School
Daniel from Carlton Public School

Solutions were also sent in by:
Gina & Sarah; Patric & Charlotte from Lord Howe Island Central School
Mahalia & Sebastian; Libby & Taite from Moama Public School
Tom & Sarah; maddie & Kate from Holy Trinity School Inverell
Jessica from Carlton Public School
Caitlin from Quandialla Central School
Caitlin from Clunes Primary
Dylan, Ewan, Joe & Rory from Brighton Catholic primary School
Zachary from Hamilton South Public School
Ella from Bellingen Public School