Okay, so:
You would want to find what 1/10 of the laptop costs. That would be the 10% of money left in Kai's account.
So,
423*.1
(you have to turn the percentage into a decimal; 10%= .10
423*.1= 42.3
So, Kai has 42.3 dollars left to buy a scanner. He only has 10% of his bank account left to spend on the scanner.
I hope this helps!
~cupcake
