Answer:
46 Blocks
Explanation:
As it is given in the question :
Harrison made a building using blocks = 124
Greyson made a building using bloks = 78
Now we need to know that how many more blocks did Harrison use than Greyson.
To calculate the difference between Harrison's block and Greyson's block used to build a building we just subtract Greyson's number of used blocks from Harrison's number of used blocks
= 124 - 78 = 46
Answer is Harrison used 46 blocks more than the number of the blocks used by Greyson.