Adam needs 40 marbles.
He has 20 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
20 marbles is less than 40 marbles. So, (1) 'Has' gets the shorter bar.
(d)
Number of more marbles that Adam needs
= 40 - 20
= 20
Answer(s): (a) 1; (b) 2; (c) 1; (d) 20