Answers:
1. There are rivets on the belts.
2. Extra information given in the problem:
a. He has 9 buckles.
b. He has 22 rivets left over.
Solution:
1. Total rivets on the belts=(12 rivets/belt)(4 belts)+(15 rivets/belt)(2 belts)
Total rivets on the belts=48 rivets+30 rivets
Total rivets on the belts=78 rivets
2. The extra information given in the problem is the information that we didn't use to solve it. In this case:
a. He has 9 buckles.
b. He has 22 rivets left over.
That would be 0.24(0.4). First, estimate the result: 0.24 is about 1/4, and (1/4)(0.4) is about 0.1.
0.24(0.4) = 0.096 (which agrees with the estimated answer, 0.1).
Making a table helps compare two or more sets of data because you can look at how much it has increased or decreased.
