We round numbers to make them easier to work with We may round a number to a multiple of 10 10 100 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 nec ID: 1020105
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1. Rounding DecimalsNBT.4
2. 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, 100, 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.
3. Why do we “ROUND” numbers? $3.09$2.79$0.99Try to add $3.09 + $2.79 + $0.99 mentally (in your head with no pencil or paper).Try to add $3.00 + $3.00 + $1.00 mentally (in your head with no pencil or paper). 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. For example, I go to the grocery store and buy:While standing in line, I want to make sure I don’t spend more than $20. 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. $6.87$7.00
4. 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. 565.55.3The nearest whole number to 5.3 is 5.
5. Education galaxy videos –rounding decimals tenths and hundredths
6. To make sure everyone rounds numbers the same way, we can follow these Rounding Rules. Let’s practice!
7. Round 7.348 to the nearest hundredth. 7.348Find the number (in the hundredths place)
8. Round 7.348 to the nearest hundredth. 7.348Find the number (in the hundredths place)
9. Round 7.348 to the nearest hundredth. 7.348Find the number (in the hundredths place)Look RIGHT next door. This number is the BOSS!BOSS! The BOSS tells the number being rounded what to do! 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”.
10. Round 7.348 to the nearest hundredth. 7.348Find the number (in the hundredths place)Look RIGHT next door. This number is the BOSS!BOSSYBOSS! The BOSS tells the number being rounded what to do! 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”.Since the 8 is more than 5, it is a BOSSY BOSS, and it tells the 4 to GET UP to a 5.
11. Round 7.348 to the nearest hundredth. 7.348Find the number (in the hundredths place)Look RIGHT next door. This number is the BOSS!BOSSYBOSS! The BOSS tells the number being rounded what to do! 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”.Since the 8 is more than 5, it is a BOSSY BOSS, and it tells the 4 to GET UP to a 5.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. 7.350
12. Round 1.195 to the nearest tenth. 1.195Find the number (in the tenths place)
13. Round 1.195 to the nearest tenth. 1.195Find the number (in the tenths place)
14. Round 1.195 to the nearest tenth. 1.195Find the number (in the tenths place)Look RIGHT next door. Bossy Boss5 or moreNice Boss4 or less
15. Round 1.195 to the nearest tenth. 1.195Find the number (in the tenths place)Look RIGHT next door. Bossy Boss5 or moreNice Boss4 or less3. 9 is a BOSSY BOSS, so it tells the 1 to GET UP to a 2. BOSSY BOSS!
16. Round 1.195 to the nearest tenth. 1.195Find the number (in the tenths place)Look RIGHT next door. Bossy Boss5 or moreNice Boss4 or less3. 9 is a BOSSY BOSS, so it tells the 1 to GET UP to a 2. 1.200
17. Round 1.195 to the nearest tenth. 1.195Find the number (in the tenths place)Look RIGHT next door. Bossy Boss5 or moreNice Boss4 or less3. 9 is a BOSSY BOSS, so it tells the 1 to GET UP to a 2. 1.200The numbers to the left of the number being rounded stay the same, and the numbers to the right (including the boss) change to zero. 5. The zeros at the end are just place holders, so they can be removed.
18. Round 1.0145 to the nearest thousandth. 1.0145Find the number (in the thousandths place)
19. Round 1.0145 to the nearest thousandth. 1.0145Find the number (in the thousandths place)
20. Round 1.0145 to the nearest thousandth. 1.0145Find the number (in the thousandths place)Look RIGHT next door. Bossy Boss5 or moreNice Boss4 or less
21. Round 1.0145 to the nearest thousandth. 1.0145Find the number (in the thousandths place)Look RIGHT next door. Bossy Boss5 or moreNice Boss4 or less3. 5 is a BOSSY BOSS, so it tells the 4 to GET UP to a 5. BOSSY BOSS!
22. Round 1.0145 to the nearest thousandth. 1.0145Find the number (in the thousandths place)Look RIGHT next door. Bossy Boss5 or moreNice Boss4 or less3. 5 is a BOSSY BOSS, so it tells the 4 to GET UP to a 5. 1.0150
23. Round 1.0145 to the nearest thousandth. Find the number (in the thousandths place)Look RIGHT next door. Bossy Boss5 or moreNice Boss4 or less3. 5 is a BOSSY BOSS, so it tells the 1 to GET UP to a 2. 0The numbers to the left of the number being rounded stay the same, and the numbers to the right (including the boss) change to zero. 5. The zeros at the end are just place holders, so they can be removed. 1.01451.015