One of my goals when teaching my students math is to help them to possess a feeling of competence and comfort with numbers in a variety of contexts.
Last week I shared 28 math tips to motivate and inspire your students. And I introduced the idea of a celebration of maths.
We should be celebrating the fact that maths influences so many aspects of our lives and we are going to have FUN exploring these varied aspects.
One of the ways that we can allow our students to feel competent and confident with numbers is to teach various mental computational strategies.
What is mental computation?
Mental computation is being able to determine the answer to a calculation or problem in one’s head.
Mental computation is an important skill that students need to be good at as as it helps them with their feeling of competence and allows them to check if answers they come to are in fact reasonable.
Learning math facts
Helping students to learn math facts and practice these facts can be challenging. Today I’m going to share another way that you can allow your students to practice their math facts and the compatible numbers mental math strategy.
What are compatible numbers?
Compatible numbers are numbers that when added produce a ‘tidy sum’, one that usually ends in zero, or multiples of 10. For example, 7 and 3; 6 and 4; 8 and 2; and 9 and 1 are considered compatible because when added they total 10 (end in zero). Also, 70 and 30; 16 and 84; 38 and 62 are also compatible numbers because when added they total 100 (end in zero).
If you’re after some other ideas for teaching this mental math strategy then have a look at my Compatible Numbers Strategy article.
Math facts and sticky notes
This activity is a nice visual way that your students can revise their math facts.
What you’ll need
- A large sheet of paper with a circle drawn on it;
- Sticky notes with compatible numbers written on them. Depending on if you are practising math facts to 10 or 100 will determine the numbers you have on the sticky notes. In the example below we explored compatible numbers totalling 100.
To complete the activity
1. Have the large sheet of paper stuck to a wall with the sticky notes stuck on the outside of the circle.
2. Select one student to come and choose 2 numbers that add to your target number and stick them together in the circle.
3. Ask the rest of the class if the two numbers add together to make the number.
4. Some questions you can ask your students include:
- How did you choose the pairs of numbers?
- How did you work that out?
- What was your strategy?
- Why did you use that strategy?
5. Continue to allow different students to come and select 2 numbers to add to the circle until all sticky notes have been used.
Some ways that you could extend or adapt this idea include:
- Get your students to make their own circles with sticky notes and swap with another student who must then find the compatible numbers to add and place in the middle.
- You could ask for 3 numbers to add to the total.
- Use decimals to find pairs of numbers that add to 10.
More activities to develop number facts
I’ve also put together a bumper math eBook that includes many activities, games and ideas to teach your students mental computation and math facts.
The mental math strategies that are covered in this pack include:
- Counting on strategy;
- Near doubles strategy;
- Compatible numbers strategy;
- Partitioning strategy; and
- Estimating strategy.
Each strategy includes:
- An explanation of the strategy with examples;
- Posters to assist in explaining the strategy;
- Activity ideas to help your students practice the strategy; and
- Games to provide further consolidation of the strategy.
The eBook also includes ideas for teaching about space, measurement, number and chance & data. This 138 page eBook is ready for your download right now. Just click the link below to find out more:
FREE Skip Counting Puzzles
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