• Double Digit Sums Step-by-Step Lesson- This one will so times trick kids, that's why I started off with it.
• Guided Lesson - The sums that are presented are very simple to provide the kids some starting success.
• Guided Lesson Explanation - A little bit of round and pound together, like my old middle school teacher use to say.
• Visually Estimate Sums and Differences 5 Pack - We pack in both skills into 10 pages total.
• Practice Worksheet - A clean cut practice sheet for you to work with. Use the lines to keep your line up set up.
• Matching Worksheet - Match the sums to their rounded totals. Five and up goes up, everything else gets rounded down.
• Group Practice Sheet - A nice pack of both addition and subtraction skills packed together for you.
• Estimating Versus Exact Worksheet - We get an idea of how relatively close we are to the answer in this one.
• Horizontal Placement - See if a simple change in number orientation affects students performance.
• Practice Worksheet - See how the two operations come into being.
• Estimating the Reality of Sums Worksheet - How far off are estimates from the real deal?
• Real World Lesson - These are the types of problems that adults face everyday that they wake up. Good practice for growing children.
• Making Sums and Differences - We give you the outcome of an addition or subtraction problem. You tell us two numbers that would fit it.
• Estimating Sums (With Arrows) - Round and then pound the numbers together.
• Skill Five Pack - Another five pack for you. Practice this skill over a series of five worksheets.
• Intermediate Lesson - Go to the whole numbers first, you'll see. We introduce the concept of rounding up to use a third digit.
• Estimating Sums and Differences Lesson and Practice - Match the sums to their rounded totals.
• Sums and Difference with Visual Estimation Worksheet - A nice day with the animals.
• More Visual Thoughts Worksheet - It's a regular math filled zoo in here.

• Answer Keys - These are for all the unlocked materials above.

Homework Sheets

Matching is always fun for students and teachers alike.

• Homework 1 - Write the letter of the estimated sum.
• Homework 2 - If the digit that becomes zero is 0, 1, 2, 3, or 4, that digit becomes a zero and the digit to be rounded (the digit immediately to the left of it) remains the same.
• Homework 3 - If the digit that becomes zero is 5, 6, 7, 8 or 9, that digit becomes a zero and the digit to be rounded is increased by one.

Practice Worksheets

We throw sums and differences in here to act as a quality practice experience.

• Practice 1 - There are both addition and subtraction problems in here.
• Practice 2 - Use the lines to your advantage.
• Practice 3 - Lay some bricks of knowledge down here.

Math Skill Quizzes

Vertical practice with lines to help guide you along. Make sure not to lose site of the sums.

• Quiz 1 - Estimate the sum of all problems.
• Quiz 2 - Straight addition here.
• Quiz 3 - A nice way to review this topic.

How to Estimate Sums

Learning estimation of sums is essential when the students go in the phase to learn mental mathematics. Solving these operations mentally helps when you have to solve a bulk of calculations when adding simple numbers is the least of your worries.

The best way to find this value is to round off to the nearest tens which makes it easier to solve. For instance, if you have two numbers, 16 and 11, to add. You can make 16 into 20 and 11 into 10. Add both 20 and 10 or a result 30, and then you can subtract the 4 which you added from 16 and add 1 which you subtracted from 11. The resultant answer is 27.

The above-mentioned method comes in handy when you are performing a bulk of calculations so that you don't have to write it. Rounding is a directly related skill to doing this properly and solving them with relative ease.