The first step is correct. 37 can be approximated to 40 so that multiplication becomes easier. The second step is also correct. 3 groups of 4 is 12. The mistake is in adding the product to 160. 37 was approximated to 40 and so the product is more than the actual answer. The correct answer should naturally be less than 160. To find the correct answer, we should subtract 12 from 160. So the right answer is 160 - 12 = 148.
