The 10’s multiplication facts are typically an easy set of facts to learn.
Before teaching the usual trick for the 10’s facts, you’ll want to make sure that your students understand the “number sense” behind multiplying by 10. You’ll want to teach them that when you multiply by 10, you simply increase the place values by one place.
For example, when you multiply 3×10, you increase the place values one place to get the product 30.
When you multiply 6×10, you increase the place values one place to get the product 60.
Once students have a good grasp of this rule, you can teach them the “adding zeros” trick.
I like to begin this by showing students a list of all of the facts, and asking them to find the rule. What do you notice about the products?
Students will discover, on their own, that when you multiply a number by 10, you just add a 0. For example, for 10×5, add a 0 to 5 to make 50. For 10×8, add a 0 to 8 to make 80.
It’s also very important to reinforce the commutative property.
This means that the order of factors does not change the product. For example, if students are faced with an equation like 7×10, they should see the 10 as one of the factors, and know that they can use the 10’s strategy to solve this equation. In this case students can think, “add a 0 to 7 to make 70.”
I’d love to help you with effective strategies for every single set of basic multiplication facts.
Join me for a free webinar outlining strategies for all of the facts, as well as an effective order for teaching the facts. Read more about the webinar and get registered HERE.