Janet thinks of a number that is more than 40 and less than 60.
1,2,4 and 7 are some of its factors. What is the number?

With DD in P4, I'm also interested to find out how to do this "estimation". Just by visually, or have to work out the problem? In the question posted by cftan, 384 x 23 = 8832 380 x 20 = 7600 400 x 20 = 8000 So the better estimate is 400 x 20 (difference of 832 from actual answer, as compared to di...

The topic on "estimation" is a bit tricky for me.

Estimate 1894 / 5

I thought the nearest would be 1890 / 5 but the answer is 2000 / 5.

Can someone advise. Many thanks.

Hi,

Pls help to advice.

Which of the following is the best estimate for 384 x 23?
(1) 380 x 20
(2) 400 x 20

Ans is (2). Isn't (1) a closer estimate?

Thanks.