Adam needs 70 marbles.
He has 50 marbles.
How many more does he need?
- Which model should we draw?
(1) Model Part-whole
(2) Model Comparison
- Is the total given?
(1) Yes
(2) No
- Who gets the shorter bar?
(1) Has
(2) Needs
- Number of more marbles that Adam needs = _____
(a)
Which model should we draw?
(1) Model Part-whole
(2) Model Comparison
We should draw a (1) Model Part-whole.
(b)
Is the total given?
(1) Yes
(2) No
(2) The total is not given.
(c)
Who gets the shorter bar?
(1) Has
(2) Needs
50 marbles is less than 70 marbles. So, (1) 'Has' gets the shorter bar.
(d)
Number of more marbles that Adam needs
= 70 - 50
= 20
Answer(s): (a) 1; (b) 2; (c) 1; (d) 20