Mental Maths

Hey there, fellow educators! If you’ve been cruising through Rainbow Facts to 10 with your students, it’s time to extend their number knowledge to Rainbow Math Facts to 20!

Rainbow Maths Facts are a mental maths strategy to help students recall facts to help solve mental calculations. In this blog post, we will discuss what rainbow math facts to 20 are and how to teach them to kids

What are Rainbow Maths Facts To 20?

Just like Rainbow Maths Facts to 10, Rainbow Facts to 20 consists of pairs of numbers that, when added together, result in a sum of 20. These facts aren’t just about addition; they also lend themselves to related subtraction facts. That means when students are mastering addition facts to 20, it’s a great opportunity to introduce and reinforce those related subtraction facts simultaneously.

You might hear them referred to as “Friends of 10,” “Build-to-10,” or “Make-to-10” facts. Using the term “rainbow facts” alongside the imagery of a rainbow aids in helping students easily recall these pairs.

Why teach these facts? Well, they’re essential for building mental math skills. By mastering these pairs, students can add quickly and accurately. It’s all about developing fluency and confidence in math.

Of course, students might face some challenges along the way, like grasping the concept or recalling the number pairs. But with practice, they’ll get there.

Here’s a list of rainbow facts to 10 that shows the pattern when extended to facts to 20. It’s a useful visual to help your students see the number pattern:

• 0 + 10 = 10 extends to 10 + 10 = 20
• 1 + 9 = 10 extends to 11 + 9 = 20
• 2 + 8 = 10 extends to 12 + 8 = 20
• 3 + 7 = 10 extends to 13 + 7 = 20
• 4 + 6 = 10 extends to 14 + 6 = 20
• 5 + 5 = 10 extends to 15 + 5 = 20
• 6 + 4 = 10 extends to 16 + 4 = 20
• 7 + 3 = 10 extends to 17 + 3 = 20
• 8 + 2 = 10 extends to 18 + 2 = 20
• 9 + 1 = 10 extends to 19 + 1 = 20

Here’s a list of the related subtraction facts to 20:

• 0 + 20 = 20 related subtraction fact 20 – 0 = 20
• 1 + 19 = 20 related subtraction fact 20 – 1 = 19
• 2 + 18 = 20 related subtraction fact 20 – 2 = 18
• 3 + 17 = 20 related subtraction fact 20 – 3 = 17
• 4 + 16 = 20 related subtraction fact 20 – 4 = 16
• 5 + 15 = 20 related subtraction fact 20 – 5 = 15
• 6 + 14 = 20 related subtraction fact 20 – 6 = 14
• 7 + 13 = 20 related subtraction fact 20 – 7 = 13
• 8 + 12 = 20 related subtraction fact 20 – 8 = 12
• 9 + 11 = 20 related subtraction fact 20 – 9 = 11
• 20 + 0 = 20 related subtraction fact 20 – 0 = 20

How To Teach Rainbow Maths Facts To 20

Teaching Rainbow Facts mental maths to kids is a great way to help them improve their basic addition skills. Here are some tips on how to do it:

1. Start with Rainbow Facts To 10: Before introducing Rainbow Facts to 20, make sure your child is familiar with the basic addition facts to 10. This will make it easier for them to understand the concept of Rainbow Facts to 20.
2. Use the Rainbow Facts Poster to show your students how to trace along a colour on the rainbow to find a partner pair.
3. Use visual aids: You can use manipulatives like coloured counters or blocks to help your child visualise the Rainbow Facts. For example, if you are teaching the Rainbow Fact for the number 16 (2 + 14 = 16), you can use two blue MAB tens and four yellow ones to represent the numbers.
4. Practice, practice, practice: Repetition is key when it comes to learning Rainbow Facts to 20. Encourage your child to practice regularly, and make sure they understand the concept before moving on to the next set of facts.
5. Introduce the subtraction facts simultaneously and build a fact family of 4 to show how the same 3 numbers can be used to create 3 more facts.