Rounding decimals has gone to the dogs with this set of task cards and printables designed to help your students apply decimal rounding to evaluate addition and subtraction equations! The 32 task cards, 2 journal inserts, and 3 activity sheets in this set are the perfect tools for helping your students with purposeful practice rounding decimals to the nearest whole.
Common Core State Standards for Mathematics addressed:
Numbers and Operations in Base Ten (5.NBT)
Understand the place value system.
• Use place value understanding to round decimals to any place. (5.NBT.4)
• 2 graphic reference sheets
• 32 task cards
• answer sheet and key
• three one-page activity sheets (scoring guides included)
I designed these cards to help my students practice applying rounding decimals to the nearest whole. The cards present a variety of addition and subtraction equations, each of them containing decimals (through hundredths) and an unknown. Most of the equations have an unknown sum or difference, but some have an unknown in place of an addend, minuend, or subtrahend to provide a higher level of challenge.
The first sixteen cards are in a multiple-choice format, presenting the students with an equation and four answer choices to choose among. The second set of sixteen cards do not provide answer choices, instead asking the students to round to the nearest whole and estimate the value of the unknown on their own.
The printables consist of two graphic reference sheet and three different one-page worksheets. The first reference sheet provides a quick explanation of the vocabulary and symbols associated with estimation. The other sheet demonstrates how to estimate the value of an unknown, using number lines to illustrate the estimated value of each decimal in the equation.
The first of the two reference sheets are half-sheets, so one can fit easily on one page of a journal or notebook. The other reference sheet is full-size. When I give students sheets of this size, I sometimes have them fold it in half and glue it across two pages of the journal, allowing it to fold open when they open their journal; alternatively, they may fold it in half and glue one half down on one journal page, folding open the sheet when they need to read it. Your students can use the journal inserts as guides while they work on the cards, as well as when they complete other tasks that relate to rounding.
The three provided worksheets can be used to evaluate student understanding of estimating unknowns when adding and subtracting decimals.
The first two worksheets are formatted similarly, and have similar types of questions, though the numbers on each are different. You can use this pair of activity pages in a variety of ways. You could give one as a pre-test, then teach your lesson and allow students to practice with the task cards, and then give the second worksheet as an independent post-test. You could also have the students work on the task cards, then complete one of the worksheet as guided practice with yourself, a partner, or a small group, and then give the second worksheet as an independent assessment. The worksheets could also be given as homework, center assignments, or any other purpose that fits your teaching style or classroom routines. Grading these activity sheets will be a breeze with the included answer keys!
The third activity sheet is an application-based task that requires students to evaluate another student’s work and to demonstrate their reasoning about decimal estimation in writing. For this task, I have included a 3-point rubric that can be used to evaluate your students’ performance.
I hope your students enjoy these resources and are able to build their ability to apply decimal rounding when adding and subtracting. – Dennis McDonald