A teacher gives students a 1-to-100 number grid with blank lines in place of many of the numbers. By filling in the blanks to complete the number grid, the students will reinforce the knowledge of where numbers belong in relation to each other. For more advanced students, teachers can create smaller grids of three to 12 blocks, in any horizontal or vertical configuration, and only one number filled in. Students then have to add or subtract horizontally by ones and vertically by tens to fill in the blank squares.
A teacher gives each student a number grid, either laminated or in a plastic sleeve, and a dry erase marker. The teacher then shows students a number on the grid followed by several arrows pointing to the left or right. Students draw a circle on the starting number, fill in the appropriate number of squares with arrows, and draw a circle on the resulting number. Once students learn to count by tens, teachers can do this exercise with vertical arrows, then a combination of vertical and horizontal arrows.
Number grids can help kids visualize counting by twos, fives, or any other number. They can also help kids learn even and odd numbers. Children can color even numbers one color and odd numbers another color or count by threes and color in every third number. Skip-counting using number grids is one way to prepare kids for later instruction in multiplication.
Number grids can be used to help students easily subtract large numbers. To find the difference between 76 and 34, for example, students can count how many tens places are between 34 and 74, then how many ones places are between 74 and 76. The answer, four tens plus two ones, or 42, is the difference between the two numbers.