Abox of 25 light bulbs is shipped to a hardware store. when it arrives, four of the bulbs are broken. predict the number of broken light bulbs in an order of 125 bulbs

First you need to divide 125 / 25 which is 5 then you do subtraction 21 x 5 which is 105, then you subtract again 125 - 105 which is 20, 20 light bulbs will be broken. Or you could have just multiplied 5 by 4 which is the amount of light bulbs that were broken which is a lot easier...