Question

Would you use count on or doubles to solve? why? 3+9

Answer 1

To solve a sum, it is best to keep counting to finally have the exact value.

So to 3 we add 9 units then it would be:

`\begin{gathered} \text{ 3}+9\text{ } \\ \text{ }(\text{1}+2)+9 \\ \text{ 3}+9;\text{ then }is\text{ duplicating a number that is to} \\ say\text{ looking }for\text{ two numbers that when } \\ \text{adding }them\text{ give you one of the values ,then }from\text{ 3 two numbers } \\ \text{that give 3 are 1 +2 , }here\text{ we double }that\text{ value.} \\ \text{then: 3+9} \\ 1+2+9 \\ So\text{ 3+9}=12 \\ \\ \end{gathered}`