+=( )
+= | += | -= | 1-= |
51×7≈ | 49×6≈ | 299+103≈ | 701−198≈ |
24×2= | 240+550= | 904-201= | 2×900= | += |
1-= | 103×5= | 196×4≈ | 20×5-100= | 72÷(107-98)= |
250+450= | 560-400= | 230×3= | 25×4×5= |
+= | 1-= | += | -= |
1003-799≈ | 197+402≈ | 198×4≈ | 81×7≈ |
55+46= | 650-380= | 1600+400= | 67+28×0= |
8×500= | 49-28= | 124×2= | 9×(55-46)= |
398×7≈ | 199+402≈ |