What number goes in the box so that 10×20×30×40×50=100×2×300×4×□?
Pick one
Solution
Nick has 6 nickels and each nickel is worth 5¢. So Nick has 6×5¢ or 30¢ in nickels.
Nick has 2 dimes and each dime is worth 10¢. So Nick has 2×10¢ or 20¢ in dimes.
Nick has 1 quarter and each quarter is worth 25¢. So Nick has 1×25¢ or 25¢ in quarters. In total, Nick has 30¢ +20¢ +25¢ or 75¢.
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