Number Chart is an interactive 100 chart, addition chart, and multiplication chart that teachers can use either as part of whole group or small group instruction. It can be accessed at https://mathies.ca/tools/NumberChart/index.html?show=true&title=Number%20Chart and in addition to being web-based can also be downloaded. It is especially useful for teachers in the primary grades.
The advantage that this site has over physical number charts is how convenient it is to turn groups of cards over instantly and how you can switch quickly between different types of charts. Clicking on the top left button gives you the option to ‘Show All’, ‘Hide All’, or ‘Flip All’ the cards:
Clicking on the button next to this gives you the option of using an addition chart (up to 12+12), a multiplication chart (up to 12×12), a 0 to 99 chart, or a 1 to 100 chart (as shown below):
Teachers can then use these in conjunction with the types of notice-and-wonder questions that they might typically use with a physical number chart. For example, when learning about doubles, teachers can hide all the numbers in the addition chart and then reveal each double (e.g. 1+1, 2+2 etc.) one at a time by tapping on the appropriate card. Questions such as ‘What will come next?’, ‘What do you notice about these numbers?’ can be asked.
Likewise, the multiplication chart can be used to reveal certain facts one at a time (as in a choral counting approach) or by focusing on, for example, the square numbers and asking students what the hidden numbers are:
The 1 to 100 chart could be used by giving a starting number then a few others that form a pattern, and then asking students what they notice, for their predictions as to how the pattern continues, and for what the pattern rule actually is. It is possible, in this case, for students to see why adding 9 is the same as adding 10 then taking 1:
There are also annotation tools should teachers wish to add ideas and information to the chart:
Overall, another great made-in-Ontario piece of software from the Mathies team.