Rounding Decimals NBT 4 Why do we ROUND
Rounding Decimals NBT. 4
Why do we “ROUND” numbers? We round numbers to make them easier to work with. We may round a number to a multiple of 10 (10, 1000, etc. ) or we may round a decimal number to the nearest whole number. Rounding allows us to solve mental math problems easier. We can use rounding in situations where an exact answer is not necessary.
For example, I go to the grocery store and buy: 9 0 $3. Why do we “ROUND” numbers? 9 7 $2. 9 9 $0. While standing in line, I want to make sure I don’t spend more than $20. If we ROUND these prices, we could say the bread costs about $3. 00, the milk costs about $3. 00, and the eggs cost about $1. 00. Try to add $3. 09 + $2. 79 + $0. 99 mentally (in your head with no pencil or paper). $6. 87 Try to add $3. 00 + $1. 00 mentally (in your head with no pencil or paper). $7. 00 It is much easier to add the rounded numbers mentally. The rounded answer is called an estimate and should be close to the exact answer.
What does it mean to “ROUND” numbers? When we round a number, we are finding the closest “friendly number” that is easier to work with. Examples of friendly numbers could be multiples of 10 or the nearest whole. Example: Round 5. 3 to the nearest whole number. 5 5. 3 5. 5 6 The nearest whole number to 5. 3 is 5.
Education galaxy videos –rounding decimals tenths and hundredths
To make sure everyone rounds numbers the same way, we can follow these Rounding Rules. Let’s practice!
Round 7. 348 to the nearest hundredth. 7. 348 1. Find the number (in the hundredths place)
Round 7. 348 to the nearest hundredth. 7. 348 1. Find the number (in the hundredths place)
Round 7. 348 to the nearest hundredth. 7. 348 BOSS! The BOSS tells the number being rounded what to do! 1. Find the number (in the hundredths place) 2. Look RIGHT next door. This number is the BOSS! If THE BOSS is 5 or more, he is a BOSSY BOSS, and he tells the number being rounded to “GET UP!” If THE BOSS is 4 or less, he is a NICE BOSS, and he tells the number “JUST REST”.
Round 7. 348 to the nearest hundredth. 7. 348 BOSSY BOSS! The BOSS tells the number being rounded what to do! 1. Find the number (in the hundredths place) 2. Look RIGHT next door. This number is the BOSS! If THE BOSS is 5 or more, he is a BOSSY BOSS, and he tells the number being rounded to “GET UP!” If THE BOSS is 4 or less, he is a NICE BOSS, and he tells the number “JUST REST”. 3. Since the 8 is more than 5, it is a BOSSY
Round 7. 348 to the nearest hundredth. 7. 348 7. 350 BOSSY BOSS! The BOSS tells the number being rounded what to do! 1. Find the number (in the hundredths place) 2. Look RIGHT next door. This number is the BOSS! If THE BOSS is 5 or more, he is a BOSSY BOSS, and he tells the number being rounded to “GET UP!” If THE BOSS is 4 or less, he is a NICE BOSS, and he tells the number “JUST REST”. 3. Since the 8 is more than 5, it is a BOSSY BOSS, and it tells the 4 to GET UP to a 5. 4. The numbers to the left of the number being rounded stay the same, and the numbers to the right (including the boss) change to zero.
Round 1. 195 to the nearest tenth. 1. 195 1. Find the number (in the tenths place)
Round 1. 195 to the nearest tenth. 1. 195 1. Find the number (in the tenths place)
Round 1. 195 to the nearest tenth. 1. 195 1. Find the number (in the tenths place) 2. Look RIGHT next door. Bossy Boss 5 or more Nice Boss 4 or less
Round 1. 195 to the nearest tenth. 1. 195 BOSSY 1. Find the number (in the tenths place) BOSS! Bossy Boss 5 or more Nice Boss 4 or less 2. Look RIGHT next door. 3. 9 is a BOSSY BOSS, so it tells the 1 to GET UP to a 2.
Round 1. 195 to the nearest tenth. 1. 195 1. 200 Bossy Boss 5 or more Nice Boss 4 or less 1. Find the number (in the tenths place) 2. Look RIGHT next door. 3. 9 is a BOSSY BOSS, so it tells the 1 to GET UP to a 2.
Round 1. 195 to the nearest tenth. 1. 195 1. 200 1. 2. 3. 2. 4. Bossy Boss 5 or more Nice Boss 4 or less Find the number (in the tenths place) Look RIGHT next door. 9 is a BOSSY BOSS, so it tells the 1 to GET UP to a The numbers to the left of the number being rounded stay the same, and the numbers to the right 5. The zeros at the end are just place (including holders, so change to zero. the boss) they can be removed.
Round 1. 0145 to the nearest thousandth. 1. 0145 1. Find the number (in the thousandths place)
Round 1. 0145 to the nearest thousandth. 1. 0145 1. Find the number (in the thousandths place)
Round 1. 0145 to the nearest thousandth. 1. 0145 Bossy Boss 5 or more Nice Boss 4 or less 1. Find the number (in the thousandths place) 2. Look RIGHT next door.
Round 1. 0145 to the nearest thousandth. 1. 0145 Bossy Boss 5 or more Nice Boss 4 or less BOSSY 1. Find the number (in the thousandths place) BOSS! 2. Look RIGHT next door. 3. 5 is a BOSSY BOSS, so it tells the 4 to GET UP to a 5.
Round 1. 0145 to the nearest thousandth. 1. 0145 1. 0150 Bossy Boss 5 or more Nice Boss 4 or less 1. Find the number (in the thousandths place) 2. Look RIGHT next door. 3. 5 is a BOSSY BOSS, so it tells the 4 to GET UP to a 5.
Round 1. 0145 to the nearest thousandth. 1. 0145 1. 0150 1. 2. 3. 2. 4. Bossy Boss 5 or more Nice Boss 4 or less Find the number (in the thousandths place) Look RIGHT next door. 5 is a BOSSY BOSS, so it tells the 1 to GET UP to a The numbers to the left of the number being rounded stay the same, and the numbers to the right 5. The zeros at the end are just place (including holders, so change to zero. the boss) they can be removed.
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