Aligned To Common Core Standard:
Grade 4 Base Ten - 4.NBT.B.4
How to Estimate Differences - Estimating differences is just like estimating sums. Difference is when you subtract one number from the other. The steps of estimation are almost the same. For example, if it's a two-digit number then our aim to estimate to the nearest 10 meaning that there are two numbers. If it is a three-digit number, then you need to round it about or make an estimation to the nearest 100. The second step is to subtract the new numbers. But remember you are not getting the exact answer. Estimation can only bring you as close as possible to the actual answer but be the accurate figure. This process is often carried out when money is involved. For example, having enough money in the supermarket to get the groceries. For example, when you have $40 and you want to buy groceries that are going to cost you around $28. So, you round it about to the nearest tenth which is $30. 58 --> 60 (Nearest tenth) 33 --> 30 (Nearest tenth) | 60 - 30 = 30. This 30 is your estimated answer and difference and not the actual answer. These worksheets and lessons are helpful when you are learning to get a ballpark idea of subtraction problems.
Printable Worksheets And Lessons
- Double Digits Step-by-Step Lesson- We start the concept of rounding and estimating with two digit numbers.
- Guided Lesson - Find the difference between two double digit numbers by estimating.
- Guided Lesson Explanation - I like to use the round, subtract zeros, finalize method for this one.
- Number Operations 5 Pack -This is a perfect reminder of the operations that you can find by rounding and estimating.
- Practice Worksheet - Ten problems for you to knock out of the park.
- Matching Worksheet - Match the differences to their estimated outcome.
I definitely recommend that you have students use the estimation arrows as a fixed technique.
- Homework 1 - If the ones place value is 4 or less, the tens place stays where it is.
- Homework 2 - If the ones place value is 5 or more, the tens place moves up one. The ones place is then changed to a 0.
- Homework 3 - To round numbers to the nearest tens place, we look at the ones place.
I start rounding in my life when I retired. I take all of my change and deposit into my grandkids college fund. We're up to six hundred dollars now.