Finding Unknown Numbers in Math

This video tutorial covers lesson 5.5 on using related facts to find unknown numbers in math problems. It explains how related facts use the same numbers in different orders to solve equations. The lesson includes examples of using related facts in addition and subtraction, and demonstrates how to use counters as a visual aid. The video also provides practical applications through word problems, helping students understand how to apply these concepts in real-life scenarios. The lesson concludes with a preview of the next topic, lesson 5.6.

What is the main purpose of using related facts in mathematics?

• To memorize numbers

• To find unknown numbers

• To practice counting

• To solve multiplication problems

In the equation 9 + ? = 11, what is the unknown number?

• 4

• 1

• 2

• 3

How can counters help in finding unknown numbers?

• By adding more counters

• By visualizing the problem

• By subtracting counters

• By multiplying counters

If 11 is equal to 3 plus an unknown number, what is the unknown number?

• 5

• 8

• 6

• 7

Emma has 12 flowers and needs 18 to fill a vase. How many more does she need?

• 6

• 5

• 4

• 7

There are 14 turtles on a log and 5 leave. How many are left?

• 7

• 8

• 9

• 10

If there are 17 children at the park and 9 are girls, how many are boys?

• 6

• 7

• 8

• 9

After 5 people leave the beach, 3 more come. How many are there now if there were initially 12?

• 11

• 10

• 9

• 8