 # Partial Sums Addition to 1,000

Students learn to use partial sums to add numbers up to 1,000.

No account needed. 8,000 schools use Gynzy 92,000 teachers use Gynzy 1,600,000 students use Gynzy

## General

Students learn to use partial sums to add numbers up to 1,000.

2.NBT.B.7
3.NBT.A.2

## Relevance

Using partial sums is useful when you want to add two numbers but can't solve the problem in your head. You can use this to add large numbers together. This is useful to determine, for example, how many hotel rooms have been booked.

## Introduction

Show a math problem on the interactive whiteboard represented by the chocolates. Ask students what the total is. Then show them the problem with money and ask students to determine the total. Ask students to explain their strategy. Then show students a quantity of blocks, which they must drag the correct number to the boxes. There is also a number place value chart to fill in.

## Development

Check that students are able to add using partial sums by asking the following questions/giving the following problems:
- Why is it useful to add with partial sums?
- What do the letters H, T, and O mean?
- Where do you always start when solving using partial sums?
- Solve these problems using partial sums: 568 + 21 and 241 + 417

## Guided practice

Students are given problems in which they must solve an addition problem using partial sums in which the problem has already been written in the chart. They are also given problems in which students are asked to place the addition problem in the chart and then solve using partial sums.

## Closing

Discuss with students that it is useful to be able to use partial sums when adding to 1,000 so you can use an easier method to add larger numbers. Check that students remember that adding using partial sums goes from left to right. Show students a math problem in which three numbers must be added together. The numbers are already in the chart. Ask students how they might solve this problem.

## Teaching tips

Students who have difficulty with adding partial sums can be supported by refreshing what the place value chart is and what it does. Ask students to practice placing numbers in the place value chart. To help distinguish, you can use different colors for each place value. Show how adding hundreds, tens, ones and then adding those totals together makes addition easier.

### The online teaching platform for interactive whiteboards and displays in schools

• Save time building lessons

• Manage the classroom more efficiently

• Increase student engagement 