You just learned how to read tables. It might not seem like it at first glance, but tables can be used for addition and subtraction, and for identifying number families. Let's look at the table we just saw about Ben and Maria's working hours. This time, though, let's add one row and one column.
| |
Monday |
Tuesday |
Total |
|
Ben |
3 |
4 |
7 |
|
Maria |
2 |
5 |
7 |
|
Total |
5 |
9 |
|
The rows of the table work just like number families. The first two numbers are the lesser (smaller) numbers. The sum (answer) is the greatest (largest) number. We add Ben's hours on Monday (3) and on Tuesday (4) to find the sum of the number of hours he worked: 7.
The columns work like number families, too. The first two numbers are the lesser numbers. The sum or difference is the greatest number. We add Ben's hours on Monday (3) and Maria's hours on Monday (2) to find the total number of hours they worked altogether on Monday: 5.
We can use number families to help us complete the chart. Let's say you want to know how many hours Maria worked in total. You can use the information in this row to find the answer. The table tells you that Maria worked two hours on Monday and five hours on Tuesday. So we simply add 2 plus 5. Our answer is 7-this is how many hours Maria worked in total.
