My name is Mandy Brockmann. I'm in grade 7. Could you help me with this math question? Tom weighed 1 pen and his calculator with 4 coins. Then he weighed his calculator and 3 pens with 12 coins. How many coins is one calculator? Thanks for looking at my question. Hi Mandy,Imagine that you have a balance and you put 1 pen and a calculator on the left side then you need 4 coins on the right to make it balance. Now if you add 2 more pens to the left side you need to put 8 more coins on the right to get a balance again. Thus the 2 additional pens weigh the same as 8 coins. In other words 1 pen is worth 4 coins. If you now go back to the original situation 1 pen and a calculator balance with 4 coins so the calculator balances with zero coins. So, how many coins is one calculator? None! Calculators are worthless. Cheers,Claude |