Today we worked on comparing decimals and ordering them on a number line. We learned that if the whole numbers are the same and you have the same number of digits after the decimal, you can compare them as if they are whole numbers. For example: 0.32, 0.236, 0.987, 0.152 Since the whole number is 0 on all of them, we are going to make sure they have them same number of digits after the decimal. As you can see, the first one does not, so we are going to add a zero to the end so that they all have 3 digits. (0.320) Now we can compare them as if they are all whole numbers, 320, 236, 987, 152. Of course we know which of these is smaller.
Tomorrow, 8/17/11 we are going to be reviewing for our test on multiplying decimals. I want the students to be able to estimate to check if their answers are reasonable. For example, if they are being asked to multiply 1.9 x 2.6, they can round each factor and multiply to check their answer. Let's say they got 49.4 and had put their decimal in the wrong place, if they estimate to check, they would multiply 2 x 3 and realize that their answer should be close to 6. This would help them to realize that they either multiplied incorrectly, or they put their decimal in the wrong spot, so they could go back and check their answer.
I will be checking out math books to each of the students today so that they have a reference at home and a way to study for tests! I hope we have a great day!!!