This math project reminds students that they can subtract using a variety of strategies. Students must draw & cross out counters in tens frames; complete a fact family (think addition to subtract); create a part-part-whole chart; hop on a number line; and complete a number sentence. Additionally, there are 3 versions of this project (easy, medium, and hard) which will help you differentiate the activity.
In the easy version, students are asked to subtract numbers within 10 and take simple hops backwards on a number line. In the medium version, students are asked to subtract within 20 and take simple hops backwards on a number line. In the hardest version, students are again asked to subtract within 20, but they are also required to decompose numbers leading to 10 when hopping backwards on the number line.
Each project is 7 pages long and includes the following:
1) a title page (the same one is used for all projects)
2) an example page where 1 problem is completed correctly using all 5 strategies (this page not only helps students, but it also helps parents)
3) 1 problem for students to complete 5 ways
4) 1 problem for students to complete 5 ways
5) 1 problem for students to complete 5 ways
6) 1 problem for students to complete 5 ways
7) writing activity – students will share their favorite strategy to use when subtracting and explain why it is their favorite
This activity is great to assign as a take-home project in all classrooms because then parents also get to see what is expected of students in the Common Core standards as well as what strategies are being used in the classroom. The following common core math standards are addressed:
1.OA.3 Apply properties of operations as strategies to add and subtract. Examples: If 8 + 3 = 11 is known, then 3 + 8 = 11 is also known. (Commutative property of addition.) To add 2 + 6 + 4, the second two numbers can be added to make a ten, so 2 + 6 + 4 = 2 + 10 = 12. (Associative property of addition.)
1.OA.6 Add and subtract within 20, demonstrating fluency for addition and subtraction within 10.
1.NBT.4 Add within 100, including adding a two-digit number and a one-digit number, and adding a two-digit number and a multiple of 10, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used. Understand that in adding two-digit numbers, one adds tens and tens, ones and ones; and sometimes it is necessary to compose a ten.
2.OA.2 Fluently add and subtract within 20 using mental strategies. By end of Grade 2, know from memory all sums of two one-digit numbers.
2.NBT.5 Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.
2.NBT.7 Add and subtract within 1000, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method.
2.NBT.9 Explain why addition and subtraction strategies work, using place value and the properties of operations.
2.MD.6 Represent whole numbers as lengths from 0 on a number line diagram with equally spaced points corresponding to the numbers 0, 1, 2, ..., and represent whole-number sums and differences within 100 on a number line diagram.