Round and estimate - 4th grade math

We go over the rounding rules in detail, and then practice rounding numbers with up to six digits. I pay special notice to numbers with lots of nines, and how the rounding works in that case. Lastly we do an estimation problem. Find more 4th grade math videos at

We go over the rounding rules in detail, and then practice rounding numbers with up to six digits. I pay special notice to numbers with lots of nines, and how the rounding works in that case. Lastly we do an estimation problem. Find more 4th grade math videos at

First we practice multiplying money amounts and estimating the final result. Secondly, I work through a word problem that involves money, using a bar model to help. This video is meant for 4th grade math.

First we practice multiplying money amounts and estimating the final result. Secondly, I work through a word problem that involves money, using a bar model to help. This video is meant for 4th grade math.

An easy lesson where we estimate products using rounding. The basic rule is to round in such a manner that makes it easy for YOU to multiply mentally. In other words, there are no "hard and fast" rules as to HOW exactly you round when estimating, because it depends on your mental math capabilities. One good principle to keep in mind is that it is helpful to round one factor UP, the other DOWN, in order to reduce or minimize the error of estimation. In one example, I do two estimations and take the AVERAGE of those as the final estimation. So that is one more strategy you can use. We also solve two word problems using estimation (instead of using long division, which could end up being more cumbersome). This is meant for 4th grade math and on up, as many math curricula never teach strategies for rounding and estimating, or how estimation can be used to solve word problems. Check out also Math Mammoth curriculum for 4th grade at It is available as an instant download and as printed books

An easy lesson where we estimate products using rounding. The basic rule is to round in such a manner that makes it easy for YOU to multiply mentally. In other words, there are no "hard and fast" rules as to HOW exactly you round when estimating, because it depends on your mental math capabilities. One good principle to keep in mind is that it is helpful to round one factor UP, the other DOWN, in order to reduce or minimize the error of estimation. In one example, I do two estimations and take the AVERAGE of those as the final estimation. So that is one more strategy you can use. We also solve two word problems using estimation (instead of using long division, which could end up being more cumbersome). This is meant for 4th grade math and on up, as many math curricula never teach strategies for rounding and estimating, or how estimation can be used to solve word problems. Check out also Math Mammoth curriculum for 4th grade at It is available as an instant download and as printed books

Here are two money-related word problems for about 4th grade. The first one asks how many $0.89 toy figures you can get with $15, which would normally be solved with division, but here we solve it using doubling and estimation. The second problem is a simple subtraction problem, BUT we find it's quicker to solve it using adding up. Mental math beats the regular subtraction algorithm here!

Here are two money-related word problems for about 4th grade. The first one asks how many $0.89 toy figures you can get with $15, which would normally be solved with division, but here we solve it using doubling and estimation. The second problem is a simple subtraction problem, BUT we find it's quicker to solve it using adding up. Mental math beats the regular subtraction algorithm here!

In this lesson, we first practice rounding money amounts to the nearest dollar or ten dollars. Then we estimate the total of a grocery bill using rounded numbers (rounding the individual items to the nearest dollar). The lesson is intended for about 4th grade math but can be used in 3rd grade also.

First in this lesson, we tackle a subtraction problem. I first estimate its result by rounding the numbers to the nearest hundred, then calculate the exact difference. Secondly we solve a word problem without using exact calculations -- just estimation. The task is to compare the cost of four piano lessons from two different piano teachers (Mathy my mascot wrote the problem!). Rounding the numbers to the nearest ten will help us find out which teacher is cheaper, and about how much Mathy the mammoth will save by choosing the cheaper teacher. This lesson is meant for 4th grade math. Check out also my other 4th grade videos at