Front-End Estimation of Products and Quotients
Aligned To Common Core Standard:
Grade 3 Operations - 3.OA.D.8
How to Get a Rough Estimate of Multiplication - If an accurate answer is not desired; however, producing a quick answer is the key while solving a bit complex multiplication questions; one should try to get an estimate instead of a precise value. There are situations like a college aptitude test where you have to solve a hundred such questions in a very limited time and keeping up with the deadline is more important than producing an accurate answer. For such situations, one can always practice on getting a rough estimate for a multiplication sum. Getting a rough estimate of the answer to a multiplication sum is a step by step process. For example, if you need to multiply 159 by 72 and get an estimate of the answer, round off both the numbers and multiply them. It gets easier this way. In this case, 160 x 70 can give you an estimate but a quicker answer than multiplying 159 by 72. In the case of decimal multiplication like multiplying 25 by 3.90, break the decimal number into 3, the numeral part, and 90, the decimal part. Then multiply 25 by 3, which is relatively a lot easier, and then multiply 25 by 90 and shift the decimal two places leftwards in whatever the answer you get. The reason for shifting the decimal point is that 90 was the double-digit decimal part. Hence, we shift the decimal point two places to the left. After getting both the answers, we add them to get the final answer. Here is a solution to the example, as mentioned above. 25 x 3.90 => 25 x 3 = 75, 25 x 90 = 2250, 2250 -> 22.50, 75 + 22.50 = 97.50 A collection of lessons and worksheets to help students quickly gauge an appropriate answer for multiplication and division problems.
Printable Worksheets And Lessons
- Step-by-Step Lesson- We cover both skills and tell you to load it up front.
- Guided Lesson - It's time for a barbecue and to find out how much you owe for your wonderful meal.
- Guided Lesson Explanation - It's a process: round them, count how many you need, and let the operations finish it up for you.
- Estimating Products Practice Worksheet - The focus here is on multiplication. You will find plenty of division below in the member's resource section.
- Estimating In Action Worksheet 2 - School store price list, we meet again!
We start with quotients, back to products, and a final skill solver.
- Homework 1 - Round the values to their nearest tens place.
- Homework 2 - Find each product. Then use rounding to check that your answers are reasonable. (Round the 3 digit number to the nearest hundred)
- Homework 3 - If Cindy wanted 5 slices of pizza or 4 hamburgers, which one would be cheaper? Estimate to find the answer.
Lollipop work, a little more multiplication work, and a snack bar order for you.
Math Skill Quizzes
Straight division work and the classroom supply list makes another appearance.