Add the hundreds, tens and ones separately.
STEP 1
42+35=
Tens
Ones
Tens
Ones
STEP 2
Add the tens column first.
4 tens + 3 tens = 7 tens
40 + 30 = 70
Tens
Ones
Tens
Ones
TeachThis.com.au (2009)
STEP 3
Add the ones column.
2 ones + 5 ones = 7 ones
2+5=7
Tens
Ones
Tens
Ones
STEP 4
42 + 35 =77
Tens
Ones
Subtract the hundreds, tens and ones separately.
STEP 1
34-12=
Tens
Ones
Tens
Ones
STEP 2
Subtract the tens column first.
3 tens - 1 ten = 2 tens
30 - 10 = 20
Tens
Ones
Tens
Ones
TeachThis.com.au (2009)
STEP 3
Subtract the ones column.
4 ones - 2 ones = 2 ones
4-2=2
Tens
Ones
Tens
Ones
STEP 4
34 - 12 =22
Tens
Ones
You must round UP the SECOND number.
STEP 1
38+48=
Tens
Ones
Tens
STEP 2
+2
Add 2 numbers
to round 48 UP to 50.
40
41
42
Tens
Ones
43
44
45
45
Ones
47
48
Tens
49
50
Ones
TeachThis.com.au (2009)
STEP 3
STEP 4
38 + 50 = 88
Tens
Ones
Tens
Ones
Take-away
2 numbers.
80
81
82
83
84
85
-2
85
87
88
89
90
88 - 2 =86
Use a number line to add the tens and ones.
STEP 1
34+23=
Tens
Ones
Tens
STEP 2
Break the number 23 into
tens and ones.
Ones
Tens
Ones
2 tens
3 ones
TeachThis.com.au (2009)
STEP 3
Add the 2 tens.
+10
+10
STEP 4
Then count on to add 3 ones.
+10
+10
+3
34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
54 + 3 =57