Five multiplied by four multiplied by seven equals what?
We know we can multiply numbers in any order and they’ll always make the same
product. So when we’re given a question with three numbers to multiply together, it’s always
worth looking to see whether we can multiply them in a different order to make
things easier for ourselves. In this problem, the first two numbers, five and four, multiply together to give us a
number that is quite straightforward to multiply by. So let’s keep things as they are. Five multiplied by four equals 20.
Now what we need to do is to multiply this number by seven. What fact do we know that could help us to multiply 20 by seven? Well, we know that 10 sevens equals 70. And so if we want to find double the amount of sevens, 20 sevens, we’re going to have
to double the answer. Two lots of 70 equals 140.
First, we multiplied five by four to get 20. And then we multiplied this answer by seven. Five multiplied by four multiplied by seven equals 140.