Adding Decade Numbers
15+10=?
25
How much is 4 groups of ten?
40
What is in the ones place?
12
2
20-10
10
15+6=?
21
35+ 10=?
45
what is 10 groups of ten?
100
What number is in the tens place?
45
4
50-20
30
26+5=?
31
35+30=?
65
How much is 2 groups of tens, and 4 ones?
24
How many tens are in the number 74?
7
35-20
15
43+9=?
52
70+5=?
38
What is 6 groups of tens, and 7 ones?
67
What does place value mean?
The position of a number that tells you how much it is worth.
65-30
35
54+16=?
70
55+40=?
52
8 groups of ten, and 9 ones.
What number is in the tens place?
146
4
95-50
45
55+35=?
90