Place Value, Number Stories and Basic Facts
As their work in mathematics progresses, children are beginning to use larger numbers. In Unit 5, children will begin to explore the system we use for writing large numbers by focusing on the idea of place value. For example, in the number 72, 7 is in the tens place, so there are “7 tens”, and 2 is in the ones place, so there are “2 ones”. Children will use base-10 blocks to represent numbers and to find the sum of two numbers. They will also use place value to determine “greater than” and “less than” relationships.
Later in the unit, children will continue to work with addition facts. Shortcuts for learning facts will be introduced. One shortcut is the turn-around rule, which states that the order in which numbers are added does not change the sum. For example 4+3 and 3+4 both equal 7. Your child will also learn the meaning of adding 0 and 1 to any number. Knowing these shortcuts will make the task of learning addition facts easier.
Children will also practice place value and addition and subtraction facts by acting out number stories. They will act out these stories using concrete objects and will begin to represent stories with number models.