Reasoning · Grade 3-2 Interpreting Graphs
Problem
Classes 1 and 2 pin the faces: big is 3, small is 1.
A pictograph only works once you know what one picture is worth; the classes that show both a total and all their faces let you back out that key.
3.MD.B.3Guess And Check54 less 29 girls leaves 25 boys.
If the whole group is 54 and 29 are girls, the rest must be boys — just take the whole minus the part.
3.NBT.A.2Work BackwardsThe readable boys total 18, so A = 7.
Add up every boys-bar you can read, then the one missing boys count must make up the difference to the boys total.
3.OA.D.8Identify SubproblemsA being half of B gives B = 14.
'Half of' run backwards is 'double', so doubling the known half gives the whole.
3.OA.A.4Guess And CheckSince the first blank is half of the second, doubling the first recovers the second.
Doubling reverses exactly what halving did, so it walks the relationship backwards to the larger number.
Being half means the whole was cut into two equal shares and one was taken, so two of those shares rebuild the whole.
Crack the picture key first, then 'total minus girls = boys' hands you ㉠ — only Grade 3 graph-reading and add/subtract needed!