Presentation on theme: "012345-2-3-4-5 counting negativelycounting positively Any number above zero is a positive number. Positive numbers are written with no sign or a + sign."— Presentation transcript:
counting negativelycounting positively Any number above zero is a positive number. Positive numbers are written with no sign or a + sign in front of them and they are counted from zero to the right.
counting negativelycounting positively Any number below zero is a negative number. Negative numbers are written with a - sign in front of them and they are counted from zero to the left. Always look at the sign in front of a number to see if it is positive or negative.
counting negativelycounting positively Positive numbers get bigger the further we move right, so 5 is bigger than 2. Negative numbers get smaller the further we move left, so -5 is smaller than -2.
counting negativelycounting positively Which word, “bigger” or “smaller”, would fit correctly In each of these gaps? -7 is ___________than is ___________than is ___________than -36 smaller bigger smaller
As you extend a number line showing negative numbers, they seem to get “bigger.”
But as the negative number gets bigger, the value gets lower. -10 is a larger number than -5, so it is further below zero. If you look at the number line you can see that -10 is less than -5. The numbers seem to increase in value as they go down the number line.
0 s 2 w 4 em -2 d -4 a What value is letter w? 8 What value is letter a? -10 Which value is bigger -10 or 8? Even though 10 is a bigger number than 8, 8 is bigger because 10 is negative.
If it helps you remember, think about the weather. As temperature gets lower the negative numbers seem to get bigger. Spring 7 C o Winter -12 C o Fall -4 C o
When the weather changes the temperature can go up or down. If a temperature goes up, gets warmer, it is a temperature increase. If a temperature goes down, gets colder, it is a temperature decrease.
During the summer when you wake up, the morning temperature could be 3 C. By lunchtime it is up to 10 C. o o This is a temperature increase of 7 C. o
This is a temperature decrease of 3 C. o In the early afternoon the temperature is 15 C. By early evening the temperature goes down to 12 C. o o
But what happens if we have negative temperatures? Example: During winter the early morning temperature could be -3 C. By lunch it is up to 6 C. oo This is a temperature increase of 9 C. o From -3 C to 0 C is 3 C. o oo ooo From 0 C to 6 C is a further 6 C. o oo The total of 3 C + 6 C makes 9 C.
From 3 C to 0 C is 3 C. o oo This is a temperature decrease of 8 C. o In the early afternoon the temperature is 3 C. By early evening the temperature goes down to -5 C. o o oo o From 0 C to -5 C is a further 5 C. ooo The total of 3 C + 5 C makes 8 C.
C o What temperature is shown on the thermometer? 2 C o
What temperature is shown on the thermometer? -5 C o C o