3rd Grade Input Output Tables Addition Worksheet: Add 98 to 970

The rule never changes inside a table. In table b, every input gets 500 more: 62 becomes 562, 220 becomes 720.

The middle column, Show working, is there on purpose. Writing 333 + 970 before the answer keeps the rule in sight.

Outputs above 1,000 go past the third grade goal, so treat table a as a stretch.

Add 98 looks hard. It is easier as add 100, then take 2 away: 295 + 100 = 395, so 295 + 98 = 393.

Add 500 is the easiest table. Only the hundreds digit changes, unless it passes 9, as in 500 + 500.

Ask your child, "Will the output be bigger or smaller than the input?" Here it is always bigger.

Check each table against the answer key.

Take turns being the machine. One person whispers a rule, like add 200. The other calls out inputs and hears the outputs. Who can guess the rule after three tries?

Praise the thinking: "You spotted that add 98 is almost add 100."