My students really love magic tricks in which they get to use a calculator.
This trick lets each student use a calculator.
A Truly Remarkable Number
Students enter 999999 into their calculator. Then they divide it by seven.
The result will be a mysterious number!
Next, students throw a die (or randomly pick a number from 1 to 6)
and multiply the result by the mysterious number. Then they arrange the
digits of the product from lowest to highest from left to right to form a six-digit number.
What is the number?
All students should get 124578 as their number.
Being able to multiply and divide fluently within 100 is essential during the early years of schooling, and the basic facts of addition subtraction and multiplication/division are a critical baseline, not only then but also during later work with fractions, decimals, ratio, proportion, and more.
Researchers have gained insights from brain research about demands on the working brain. As students begin to learn math facts, their brains are focused on those basic computations, but as students become automatic with basic facts, their brains are then able to focus on other aspects of the task like the challenges of place value, decimals, or fractions. Being automatic with basic facts frees the brain to focus on other math processes. Committing basic math facts to memory speeds up math tasks. As math tasks increase in complexity, they often require multiple steps to find the solution.
Because basic facts are so important for my students to master, and I have more than half of my class that does not have them mastered, I choose an oral division facts practice for this warm up. The PowerPoint slides change every 3 seconds. I encourage my students to yell their answers "loud and proud."
For this warm up, students practice basic division facts for numbers divided by three and four.
Students use Math Practice Standard 4 today as they explore how to use a place value chart to model division. I begin this lesson by instructing students to draw a place value chart on their personal white boards. Their place value chart only needs to include ones and tens.
I tell students that for today, we are going to assume we need to find how many groups to make. I tell students to model on their boards, with me, 6 ÷ 3. Students should draw 3 groups below.
I ask students questions like; Can we distribute 6 ones into 3 groups? We can think of it like dealing cards or candy evenly among 3 people. First, put one in each group. Cross off the ones one at a time as you distribute them evenly. Next, put another one in each group if you are able. Continue this until all of the ones are distributed. I ask students if there are any remainders. I explicitly call the numbers by their names as well, dividend, divisor, quotient and remainder.