We wrote the complete answer or solution to the problem and the numbers that appear in the problem. We wrote the equation as we already knew that 5 plus 4 is 9
We put the biggest number in our heads and then we go on counting.
Here we underlined what we did not know before. In one of the calculations we are adding but in the other one we are taking away. The symbol equal means that if you put the two numbers together the result is....