Adding Within 1,000 Using an Open Number Line

This lesson teaches how to add numbers within 1,000 using an open number line. It reviews place value and the commutative property of addition, demonstrating how open number lines can visualize addition by hopping in increments of hundreds, tens, and ones. The lesson also covers alternative hopping strategies and solving equations with unknown addends. By the end, students will understand how to use open number lines flexibly to find sums.

What is the commutative property of addition?

• Addition results in a smaller number.

• Numbers can be added in any order to get the same sum.

• Numbers must be added in a specific order.

• Addition is only possible with whole numbers.

How does an open number line help in addition?

• It restricts the addition to tens only.

• It requires exact markings for each number.

• It provides a fixed path for addition.

• It allows visualization of addition by hopping in increments.

When using an open number line, why is it important to keep track of where you land after each hop?

• To make sure you are adding correctly.

• To ensure you don't skip any numbers.

• To avoid going over the target number.

• To remember the sequence of numbers.

What is a common misunderstanding about hopping on an open number line?

• You can only hop in order from hundreds to ones.

• You can hop in any order that makes sense.

• You must hop by tens first.

• You cannot hop by ones.

In the example of solving 351 plus blank equals 738, what is the first step?

• Start with the answer.

• Start with the smallest addend.

• Start with the middle number.

• Start with the largest addend.

How many hops are needed to solve 351 plus blank equals 738?

• 387 hops

• 4 hops

• 3 hops

• 5 hops

What is the final step in solving an addition problem using an open number line?

• Add together all the hops taken.

• Subtract the hops from the total.

• Multiply the hops by the largest number.

• Divide the hops by the smallest number.