Estimates help us predict the reasonableness of an answer. Having students make an estimate before they perform the calculation, and even writing the estimate next to the problem, can help them to focus on making the numbers (and the problem) make sense. Example: 3.2 x 9.8 = Students use benchmarks to determine that 3.2 is close to 3 and 9.8 is close to 10, therefore, a reasonable estimate would be 3 x 10 = 30. If students perform the actual…
Here’s a super simple activity that helps students to “see” multiplication facts. It’s also a great way for them to see the connection between addition and subtraction as they “use addition to find the total number of objects arranged in rectangular arrays” (CCSSM 2.OA.C.4) and to “interpret products of whole numbers” (CCSSM 3.OA.A.1). Using inch graph paper, have students make rectangular arrays and record the rows (horizontal) and columns (vertical) as multiplication equations. This is a good time to discuss…
Mathematical properties are actually quite useful when it comes to making sense of math. For example, the commutative property of addition helps make adding numbers a little easier. If we know that the order the numbers are added does not matter, then in the problem 2 + 9, adding the 2 onto the 9 is easier and more efficient than adding the 9 onto the 2. The Common Core State Standards in Mathematics requires all third grade students to know…
We’re surrounded by line segments. These line segments create parallel and perpendicular lines, and acute, obtuse and right angles. Looking for them in our environment is a great way to reinforce them. Ask your kids: Who can find a set of parallel lines? …perpendicular lines? …an acute angle? Pretty soon, they’ll be seeing nothing but lines and angles in the tiles on the floor, the branches of the trees, the way an ice hockey puck hits the wall… For older…
I’ve said it before, but it’s important to say it again…understanding fractions begins with understanding the whole and the pieces that make it up. The question below is a good way to get students to reflect on the idea that, with fractions, each piece names one equal part. The CCSSM identifies each part as a ‘unit fraction’. Posing this question is a great opportunity to focus on the CCSSM Standards for Mathematical Practice, Construct viable arguments and critique the reasoning…