mental math addition strategies for preschoolers

H's school is participating in the World Education Games this coming March and being a kiasu school, the teacher told us parents to let our kids practise at home in the weeks leading up to the games. I always thought that H is good in maths, well he does know how to perform addition and subtraction but I guess he doesn't have the speed. So being a kiasu mom, I guess I'd need to teach him some basic mental math strategies to boost his speed in doing sums.

I came across this post by Shelly Gray and thought the strategies to be most apt for a preschooler like H. Here's a summary of the 6 strategies:

1. Counting On - Counting on means that you start with the biggest number in an equation, and then count up. For example, in the equation 5+3, you want students to start with the "5" in their heads, and then count up, "6, 7, 8." This is to discourage students from counting like, "1, 2, 3, 4, 5.....6, 7, 8." Students also need to be taught that if an equation looks like this: "2+6," they still should start with the bigger number in this case "6" and count up "7, 8." I know Math Monkey teaches this. Kids are taught to have a mental picture of the numbers 1-9 (made up of dots) so that they can use the 'counting on' strategy without having to count with fingers.

2. Doubles - Doubles are all around us; think of fingers and toes - 5+5, wheels on a car - 2+2, or the eggs in a carton - 6+6. When students know their doubles well, they should no longer have to think about the equation to solve it. Rather, the answer becomes automatic. This means that the student has developed automaticity. For example, when a student sees the equation 8+8, he should know that it equals 16 without even stopping to think. Building a strong foundation of doubles will help students with the next strategy, Doubles Plus One.

3. Doubles Plus One - This strategy is a natural progression from the doubles. It includes using a known fact and building on it. For example, in the equation 5+6, a student could think, "I know that 5+5 makes 10, and one more makes 11." This strategy will likely require a bit more teaching than the previous two, but it will be well worth it; when students know their doubles and doubles plus one facts, they know 25% of the addition table!!

 

4. Making Ten - The making ten strategy involves memorizing the number combinations that add to ten. This includes 7 and 3, 8 and 2, & 5 and 5. Again, it is important that students develop automaticity with regards to these facts so that when they see a combination, they quickly know that it is a making ten combination. Once students begin to use this strategy, "counting on" becomes unnecessary in some circumstances. Again I know Math Monkey teaches this. Kids are taught to draw a 'ten point circle'. The  numbers opposite each other are friends, i.e. number pair that sums up to 10.

 

5. Making Multiples of Ten - This strategy is a natural follow-up to making ten, as it uses the same number combinations in a different way. When teaching this strategy, students will learn to use the making ten facts in equations such as 27+3. In this case, students will see the ones digits and realize that 7 and 3 make 10, so 27 and 3 makes 30.

 

6. Front End Addition - This is perhaps one of the most powerful mental math strategies out there. Front end addition involves adding numbers from left to right, eliminating the need for carrying. For example, 54+19. You would do 50+10=60, then 4+9=13 and finally add up the 2 numbers, i.e. 60+13=73