Abacus Math Program – Lesson 12 – The 5/10 Pair Combination Part 2

Lesson 11 the 5/10 Pair Combination Part 1, we introduced the 5/10 pair combination for addition. Here in Lesson 12 Part 2 we will look at the 5/10 pair combination for subtraction. Just like in Lesson 11 Part 1 these examples will demonstrate how we use the 10 pair subtraction rule but instead of directly adding the

Abacus Math Program – Lesson 11 – The 5/10 Pair Combination Part 1

So far in Lesson 5, 6, 7, and 8 we introduced addition and subtraction with 10 pair complements when the operation requires more than 1 rod. In Lesson 9 and 10 we introduced addition and subtraction with 5 pair complements when the operation is done on a single rod, i.e. no carry or borrow is required from

Abacus Math Program – Lesson 10 – Five Pair Complement Part 2

In Lesson 9 Five Pair Part 1 we examined the 5 pair addition rule. Here in Lesson 10 Part 2 we are going to examine the 5 pair subtraction rule. In review there are only two 5 pair complements to consider: 4-1 and 3-2. Let’s take a look at the 5 pair subtraction rule in some examples such as

Abacus Math Program – Lesson 9 – Five Pair Complement Part 1

We are now half way through the Rightlobemath.com skill training program. So far we have learned to represent base 10 numbers on the abacus, add and subtract with 10 pair complements when the operation involves more than 1 rod. If you are not familiar with these concepts please go back through the online abacus math program lessons starting with Lesson

Abacus Math Program – Lesson 8 – Ten Pair Complement Subtraction Part 2

Continuing from Lesson 7 Subtraction Part 1 we will look at a few more 10 pair complement subtraction examples. Again there are 5 possible 10 pair complements: 9-1, 8-2, 7-3, 6-4, 5-5. All of these pairs are reversible meaning we can use the complement pair, 9-1, for both the problem 10-1 just as we can use the same pair

Abacus Math Program – Lesson 7 – Ten Pair Complement Subtraction Part 1

In Lesson 5 and Lesson 6 we introduced the idea of 10 pair complement addition on the abacus. Here in Lesson 7 we will introduce the concept of subtraction with 10 pair complements. In review, there are only 5 possible 10 pair complements: 9-1, 8-2, 7-3, 6-4, 5-5. In the case where we want to subtract a number from a