Rounding
Round the number 57
60
Estimate the sum 81 + 16
100
When we round the number 670, which number tells us to round up or down?
7
Find the sum 86 + 32
118
Find the sum 30 + 71
101
Round the number 650
700
Estimate the sum 950 + 220
1200
What are the three addition strategies we learned called?
(Finding the exact answer)
2) Jump strategy (number line)
3) Standard algorithm
Find the sum 764 + 381
1 145
Find the sum 129 + 873
1 002
Round the number 8 289
8 000
Estimate the sum 6 790 + 2 355
9 000
When we use the jump strategy do we put the biggest or smallest number at the start of the number line?
Biggest
Find the sum 1,466 + 4,872
6 338
Find the sum 3,908 + 4,654
8 562
Round the number 9 502
10 000
Estimate the sum 7 520 + 9 961
18 000
When using the standard algorithm to add and you end up with a two digit number, what is it called when you take the ones place and put it in the solution and the tens place goes above the next row?
Regrouping
Find the sum 7,485 + 9,096
16 581
Find the sum 6,387 + 5,538
11 925
Round the number 45 201
50 000
Estimate the sum 12 784 + 34 091
40 000
What is the most efficient strategy?
Standard algorithm
Find the sum 61,753 + 92,621
154 374
Find the sum 19,789 + 78,614
98 403