Tuesday 5th January 2021
LC- To divide whole numbers.
How would you solve the following problem?
How did you do it? Consider the questions below.
How else can we represent 2 km? Can we say 2000 m? My friend says we can divide 2000 by 10. Would this be helpful? How can we be sure? What would this tell us? If each flag should be 200 m apart, how many kilometres is that? What would 200 m be in kilometres?
Can we also find the answer by finding 2 km ÷ 10?
2km (or 2) can be rewritten as 20 tenths, 200 hundredths and 2000 thousandths. Think back to the cubes we looked at yesterday. The equation for 2 ÷ 10 can be rewritten as 20 tenths ÷ 10, and that will make the division easier to do.
So this tells us that 1 whole one is the same as 10/10, 100/100 or 1000/1000.
So 2 whole ones is 20/10 200/100 or 2000/1000.
It is saying that if we turn 2km into 20 tenths then it is easy to divide 20 by 10.
Let's look further.
Using this idea, can you show how you can rewrite the equations for 32 ÷ 10, 32 ÷ 100 and 32 ÷ 1000 to find the answers.
Can you see any pattern when a 1-digit number is divided by 10, 100 and 1000. What about when a 2-digit number is divided by 10, 100 and 1000?
Now let's look at the guided practice. Record the answers in your book.