15: Which number rounds to 0 when rounding to the thousands?
a) 812
b) 521
c) 489
d) 501
Most students got this one wrong. One student drew a number line and got it right.
Other tricky questions involved rounding first, then doing the subtraction.
Kara is reading a book with 689 pages. If she read 341, about how many does she have to go?
a)100
b) 200
c) 300
d)400
The correct answer is d) according to the test key, but I also gave credit on c) IF the student showed their work.
Which brings up a great point...
The students who are doing the very best in math are taking my advice....
1)Draw a picture.
2) Figure it out on scratch paper.
3) Always, always, always ESTIMATE first!!!!
35+(7+60)=
a. 35+7+35
b. (7+60)+60
c. 7+60+35
d. 37+60
A majority of students botched this one, perhaps because we didn't talk about the Commutative Property enough...it was surprising how many students didn't pay real close attention on this question!
Most of the other errors involved rounding to the wrong place value. For example, rounding to the 1,000s instead of hundreds made for many wrong answers.
As usual, I let students correct their errors for a better grade.
Chapter 4
Saw basic multiplication errors, especially with addends. For example, a problem like, 487x8 presents troubles in the tens column, where the problem requires "8x8+6" to be correct.
Please work with your student on math facts such as the above!