A bike shop has 8 red, 5 blue, 12 black, and 9 white bikes. Write an expression that shows how many more black bikes than red bikes there are.
Let's see. You just said there are 12 black and 8 red.
How many more than 8 is 12?
For the "expression", write down what numbers you subtract to get the answer.
To find the difference between the number of black bikes and red bikes, we need to subtract the number of red bikes from the number of black bikes.
Let's define the variables:
R = number of red bikes = 8
B = number of blue bikes = 5
Bl = number of black bikes = 12
W = number of white bikes = 9
To calculate the difference between black bikes and red bikes, we can use the expression:
Bl - R
Substituting the values, we get:
12 - 8 = 4
There are 4 more black bikes than red bikes.