Here’s my latest What Do You Notice? poster. All you need is inch graph paper, a black sharpie, and small circular stickers (or two different colored sharpie pens to draw in the circles).
3-5: multiplication, even/odd numbers, multiples of 3, square numbers
Crossed lines is an easy strategy for learning multiplication facts. The horizontal and vertical lines represent the factors in the multiplication problem. For example, in the problem 4 x 3, students would draw 4 horizontal lines and then intersect them with 3 vertical lines as is shown in the last example above. The intersection of the lines is the answer to the problem. So for 4 x 3, there would be 12 intersections.
Here’s what it looked like at the event: